Replaces literal {} created lookup tables with Object.create

src/core/chunked_stream.js

@@ -313,9 +313,9 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
 
     this.currRequestId = 0;
 
-    this.chunksNeededByRequest = {};
+    this.chunksNeededByRequest = Object.create(null);
-    this.requestsByChunk = {};
+    this.requestsByChunk = Object.create(null);
-    this.promisesByRequest = {};
+    this.promisesByRequest = Object.create(null);
     this.progressiveDataLength = 0;
 
     this._loadedStreamCapability = createPromiseCapability();
@@ -341,9 +341,9 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
     _requestChunks: function ChunkedStreamManager_requestChunks(chunks) {
       var requestId = this.currRequestId++;
 
-      var chunksNeeded;
       var i, ii;
-      this.chunksNeededByRequest[requestId] = chunksNeeded = {};
+      var chunksNeeded = Object.create(null);
+      this.chunksNeededByRequest[requestId] = chunksNeeded;
       for (i = 0, ii = chunks.length; i < ii; i++) {
         if (!this.stream.hasChunk(chunks[i])) {
           chunksNeeded[chunks[i]] = true;

src/core/evaluator.js

@@ -731,7 +731,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
       var self = this;
       var xref = this.xref;
-      var imageCache = {};
+      var imageCache = Object.create(null);
 
       assert(operatorList);
 
@@ -1054,7 +1054,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
       // The xobj is parsed iff it's needed, e.g. if there is a `DO` cmd.
       var xobjs = null;
-      var xobjsCache = {};
+      var xobjsCache = Object.create(null);
 
       var preprocessor = new EvaluatorPreprocessor(stream, xref, stateManager);
 
@@ -2093,7 +2093,7 @@ var TranslatedFont = (function TranslatedFontClosure() {
       var charProcs = this.dict.get('CharProcs').getAll();
       var fontResources = this.dict.get('Resources') || resources;
       var charProcKeys = Object.keys(charProcs);
-      var charProcOperatorList = {};
+      var charProcOperatorList = Object.create(null);
       for (var i = 0, n = charProcKeys.length; i < n; ++i) {
         loadCharProcsPromise = loadCharProcsPromise.then(function (key) {
           var glyphStream = charProcs[key];
@@ -2147,7 +2147,7 @@ var OperatorList = (function OperatorListClosure() {
     this.messageHandler = messageHandler;
     this.fnArray = [];
     this.argsArray = [];
-    this.dependencies = {};
+    this.dependencies = Object.create(null);
     this._totalLength = 0;
     this.pageIndex = pageIndex;
     this.intent = intent;
@@ -2227,7 +2227,7 @@ var OperatorList = (function OperatorListClosure() {
         pageIndex: this.pageIndex,
         intent: this.intent
       }, transfers);
-      this.dependencies = {};
+      this.dependencies = Object.create(null);
       this.fnArray.length = 0;
       this.argsArray.length = 0;
     }

src/core/font_renderer.js

@@ -609,7 +609,7 @@ var FontRendererFactory = (function FontRendererFactoryClosure() {
   var noop = '';
 
   function CompiledFont(fontMatrix) {
-    this.compiledGlyphs = {};
+    this.compiledGlyphs = Object.create(null);
     this.fontMatrix = fontMatrix;
   }
   CompiledFont.prototype = {

src/core/fonts.js

@@ -469,7 +469,7 @@ var Font = (function FontClosure() {
     this.isType3Font = properties.isType3Font;
     this.sizes = [];
 
-    this.glyphCache = {};
+    this.glyphCache = Object.create(null);
 
     var names = name.split('+');
     names = names.length > 1 ? names[1] : names[0];
@@ -1218,6 +1218,7 @@ var Font = (function FontClosure() {
     },
 
     exportData: function Font_exportData() {
+      // TODO remove enumerating of the properties, e.g. hardcode exact names.
       var data = {};
       for (var i in this) {
         if (this.hasOwnProperty(i)) {
@@ -1668,7 +1669,7 @@ var Font = (function FontClosure() {
         var newGlyfData = new Uint8Array(oldGlyfDataLength);
         var startOffset = itemDecode(locaData, 0);
         var writeOffset = 0;
-        var missingGlyphData = {};
+        var missingGlyphData = Object.create(null);
         itemEncode(locaData, 0, writeOffset);
         var i, j;
         for (i = 0, j = itemSize; i < numGlyphs; i++, j += itemSize) {
@@ -2100,8 +2101,16 @@ var Font = (function FontClosure() {
       var numTables = header.numTables;
       var cff, cffFile;
 
-      var tables = { 'OS/2': null, cmap: null, head: null, hhea: null,
+      var tables = Object.create(null);
-                     hmtx: null, maxp: null, name: null, post: null };
+      tables['OS/2'] = null;
+      tables['cmap'] = null;
+      tables['head'] = null;
+      tables['hhea'] = null;
+      tables['hmtx'] = null;
+      tables['maxp'] = null;
+      tables['name'] = null;
+      tables['post'] = null;
+
       var table;
       for (var i = 0; i < numTables; i++) {
         table = readTableEntry(font);
@@ -2118,7 +2127,8 @@ var Font = (function FontClosure() {
       if (!isTrueType) {
         // OpenType font
         if ((header.version === 'OTTO' && properties.type !== 'CIDFontType2') ||
-            !tables.head || !tables.hhea || !tables.maxp || !tables.post) {
+            !tables['head'] || !tables['hhea'] || !tables['maxp'] ||
+            !tables['post']) {
           // no major tables: throwing everything at CFFFont
           cffFile = new Stream(tables['CFF '].data);
           cff = new CFFFont(cffFile, properties);
@@ -2128,20 +2138,20 @@ var Font = (function FontClosure() {
           return this.convert(name, cff, properties);
         }
 
-        delete tables.glyf;
+        delete tables['glyf'];
-        delete tables.loca;
+        delete tables['loca'];
-        delete tables.fpgm;
+        delete tables['fpgm'];
-        delete tables.prep;
+        delete tables['prep'];
         delete tables['cvt '];
         this.isOpenType = true;
       } else {
-        if (!tables.loca) {
+        if (!tables['loca']) {
           error('Required "loca" table is not found');
         }
-        if (!tables.glyf) {
+        if (!tables['glyf']) {
           warn('Required "glyf" table is not found -- trying to recover.');
           // Note: We use `sanitizeGlyphLocations` to add dummy glyf data below.
-          tables.glyf = {
+          tables['glyf'] = {
             tag: 'glyf',
             data: new Uint8Array(0),
           };
@@ -2149,21 +2159,21 @@ var Font = (function FontClosure() {
         this.isOpenType = false;
       }
 
-      if (!tables.maxp) {
+      if (!tables['maxp']) {
         error('Required "maxp" table is not found');
       }
 
-      font.pos = (font.start || 0) + tables.maxp.offset;
+      font.pos = (font.start || 0) + tables['maxp'].offset;
       var version = font.getInt32();
       var numGlyphs = font.getUint16();
       var maxFunctionDefs = 0;
-      if (version >= 0x00010000 && tables.maxp.length >= 22) {
+      if (version >= 0x00010000 && tables['maxp'].length >= 22) {
         // maxZones can be invalid
         font.pos += 8;
         var maxZones = font.getUint16();
         if (maxZones > 2) { // reset to 2 if font has invalid maxZones
-          tables.maxp.data[14] = 0;
+          tables['maxp'].data[14] = 0;
-          tables.maxp.data[15] = 2;
+          tables['maxp'].data[15] = 2;
         }
         font.pos += 4;
         maxFunctionDefs = font.getUint16();
@@ -2175,56 +2185,57 @@ var Font = (function FontClosure() {
         // oracle's defect (see 3427), duplicating first entry
         dupFirstEntry = true;
         numGlyphs++;
-        tables.maxp.data[4] = numGlyphs >> 8;
+        tables['maxp'].data[4] = numGlyphs >> 8;
-        tables.maxp.data[5] = numGlyphs & 255;
+        tables['maxp'].data[5] = numGlyphs & 255;
       }
 
-      var hintsValid = sanitizeTTPrograms(tables.fpgm, tables.prep,
+      var hintsValid = sanitizeTTPrograms(tables['fpgm'], tables['prep'],
                                           tables['cvt '], maxFunctionDefs);
       if (!hintsValid) {
-        delete tables.fpgm;
+        delete tables['fpgm'];
-        delete tables.prep;
+        delete tables['prep'];
         delete tables['cvt '];
       }
 
       // Ensure the hmtx table contains the advance width and
       // sidebearings information for numGlyphs in the maxp table
-      sanitizeMetrics(font, tables.hhea, tables.hmtx, numGlyphs);
+      sanitizeMetrics(font, tables['hhea'], tables['hmtx'], numGlyphs);
 
-      if (!tables.head) {
+      if (!tables['head']) {
         error('Required "head" table is not found');
       }
 
-      sanitizeHead(tables.head, numGlyphs, isTrueType ? tables.loca.length : 0);
+      sanitizeHead(tables['head'], numGlyphs,
+                   isTrueType ? tables['loca'].length : 0);
 
-      var missingGlyphs = {};
+      var missingGlyphs = Object.create(null);
       if (isTrueType) {
-        var isGlyphLocationsLong = int16(tables.head.data[50],
+        var isGlyphLocationsLong = int16(tables['head'].data[50],
-                                         tables.head.data[51]);
+                                         tables['head'].data[51]);
-        missingGlyphs = sanitizeGlyphLocations(tables.loca, tables.glyf,
+        missingGlyphs = sanitizeGlyphLocations(tables['loca'], tables['glyf'],
                                                numGlyphs, isGlyphLocationsLong,
                                                hintsValid, dupFirstEntry);
       }
 
-      if (!tables.hhea) {
+      if (!tables['hhea']) {
         error('Required "hhea" table is not found');
       }
 
       // Sanitizer reduces the glyph advanceWidth to the maxAdvanceWidth
       // Sometimes it's 0. That needs to be fixed
-      if (tables.hhea.data[10] === 0 && tables.hhea.data[11] === 0) {
+      if (tables['hhea'].data[10] === 0 && tables['hhea'].data[11] === 0) {
-        tables.hhea.data[10] = 0xFF;
+        tables['hhea'].data[10] = 0xFF;
-        tables.hhea.data[11] = 0xFF;
+        tables['hhea'].data[11] = 0xFF;
       }
 
       // Extract some more font properties from the OpenType head and
       // hhea tables; yMin and descent value are always negative.
       var metricsOverride = {
-        unitsPerEm: int16(tables.head.data[18], tables.head.data[19]),
+        unitsPerEm: int16(tables['head'].data[18], tables['head'].data[19]),
-        yMax: int16(tables.head.data[42], tables.head.data[43]),
+        yMax: int16(tables['head'].data[42], tables['head'].data[43]),
-        yMin: int16(tables.head.data[38], tables.head.data[39]) - 0x10000,
+        yMin: int16(tables['head'].data[38], tables['head'].data[39]) - 0x10000,
-        ascent: int16(tables.hhea.data[4], tables.hhea.data[5]),
+        ascent: int16(tables['hhea'].data[4], tables['hhea'].data[5]),
-        descent: int16(tables.hhea.data[6], tables.hhea.data[7]) - 0x10000
+        descent: int16(tables['hhea'].data[6], tables['hhea'].data[7]) - 0x10000
       };
 
       // PDF FontDescriptor metrics lie -- using data from actual font.
@@ -2232,10 +2243,10 @@ var Font = (function FontClosure() {
       this.descent = metricsOverride.descent / metricsOverride.unitsPerEm;
 
       // The 'post' table has glyphs names.
-      if (tables.post) {
+      if (tables['post']) {
-        var valid = readPostScriptTable(tables.post, properties, numGlyphs);
+        var valid = readPostScriptTable(tables['post'], properties, numGlyphs);
         if (!valid) {
-          tables.post = null;
+          tables['post'] = null;
         }
       }
 
@@ -2287,7 +2298,7 @@ var Font = (function FontClosure() {
         var hasEncoding =
           properties.differences.length > 0 || !!properties.baseEncodingName;
         var cmapTable =
-          readCmapTable(tables.cmap, font, this.isSymbolicFont, hasEncoding);
+          readCmapTable(tables['cmap'], font, this.isSymbolicFont, hasEncoding);
         var cmapPlatformId = cmapTable.platformId;
         var cmapEncodingId = cmapTable.encodingId;
         var cmapMappings = cmapTable.mappings;
@@ -2394,7 +2405,7 @@ var Font = (function FontClosure() {
       // Converting glyphs and ids into font's cmap table
       var newMapping = adjustMapping(charCodeToGlyphId, properties);
       this.toFontChar = newMapping.toFontChar;
-      tables.cmap = {
+      tables['cmap'] = {
         tag: 'cmap',
         data: createCmapTable(newMapping.charCodeToGlyphId, numGlyphs)
       };
@@ -2408,8 +2419,8 @@ var Font = (function FontClosure() {
       }
 
       // Rewrite the 'post' table if needed
-      if (!tables.post) {
+      if (!tables['post']) {
-        tables.post = {
+        tables['post'] = {
           tag: 'post',
           data: createPostTable(properties)
         };
@@ -2429,15 +2440,15 @@ var Font = (function FontClosure() {
       }
 
       // Re-creating 'name' table
-      if (!tables.name) {
+      if (!tables['name']) {
-        tables.name = {
+        tables['name'] = {
           tag: 'name',
           data: createNameTable(this.name)
         };
       } else {
         // ... using existing 'name' table as prototype
-        var namePrototype = readNameTable(tables.name);
+        var namePrototype = readNameTable(tables['name']);
-        tables.name.data = createNameTable(name, namePrototype);
+        tables['name'].data = createNameTable(name, namePrototype);
       }
 
       var builder = new OpenTypeFileBuilder(header.version);
@@ -2855,7 +2866,7 @@ var Font = (function FontClosure() {
       if (this.cMap) {
         // composite fonts have multi-byte strings convert the string from
         // single-byte to multi-byte
-        var c = {};
+        var c = Object.create(null);
         while (i < chars.length) {
           this.cMap.readCharCode(chars, i, c);
           charcode = c.charcode;
@@ -3442,13 +3453,13 @@ var Type1Parser = (function Type1ParserClosure() {
       var stream = this.stream;
 
       var subrs = [], charstrings = [];
+      var privateData = Object.create(null);
+      privateData['lenIV'] = 4;
       var program = {
         subrs: [],
         charstrings: [],
         properties: {
-          'privateData': {
+          'privateData': privateData
-            'lenIV': 4
-          }
         }
       };
       var token, length, data, lenIV, encoded;
@@ -3770,7 +3781,7 @@ Type1Font.prototype = {
     }
     var encoding = properties.builtInEncoding;
     if (encoding) {
-      var builtInEncoding = {};
+      var builtInEncoding = Object.create(null);
       for (var charCode in encoding) {
         glyphId = glyphNames.indexOf(encoding[charCode]);
         if (glyphId >= 0) {
@@ -3904,7 +3915,7 @@ Type1Font.prototype = {
     ];
     for (i = 0, ii = fields.length; i < ii; i++) {
       var field = fields[i];
-      if (!properties.privateData.hasOwnProperty(field)) {
+      if (!(field in properties.privateData)) {
         continue;
       }
       var value = properties.privateData[field];
@@ -4655,7 +4666,7 @@ var CFFParser = (function CFFParserClosure() {
                                                     properties,
                                                     strings,
                                                     charset) {
-      var encoding = {};
+      var encoding = Object.create(null);
       var bytes = this.bytes;
       var predefined = false;
       var hasSupplement = false;
@@ -4851,7 +4862,7 @@ var CFFDict = (function CFFDictClosure() {
     this.opcodes = tables.opcodes;
     this.order = tables.order;
     this.strings = strings;
-    this.values = {};
+    this.values = Object.create(null);
   }
   CFFDict.prototype = {
     // value should always be an array
@@ -5048,7 +5059,7 @@ var CFFFDSelect = (function CFFFDSelectClosure() {
 // filling in that offset once it's known.
 var CFFOffsetTracker = (function CFFOffsetTrackerClosure() {
   function CFFOffsetTracker() {
-    this.offsets = {};
+    this.offsets = Object.create(null);
   }
   CFFOffsetTracker.prototype = {
     isTracking: function CFFOffsetTracker_isTracking(key) {

src/core/function.js

@@ -434,7 +434,7 @@ var PDFFunction = (function PDFFunctionClosure() {
       var evaluator = new PostScriptEvaluator(code);
       // Cache the values for a big speed up, the cache size is limited though
       // since the number of possible values can be huge from a PS function.
-      var cache = {};
+      var cache = Object.create(null);
       // The MAX_CACHE_SIZE is set to ~4x the maximum number of distinct values
       // seen in our tests.
       var MAX_CACHE_SIZE = 2048 * 4;

src/core/network.js

@@ -52,8 +52,8 @@ var NetworkManager = (function NetworkManagerClosure() {
       };
 
     this.currXhrId = 0;
-    this.pendingRequests = {};
+    this.pendingRequests = Object.create(null);
-    this.loadedRequests = {};
+    this.loadedRequests = Object.create(null);
   }
 
   function getArrayBuffer(xhr) {

src/core/obj.js

@@ -229,9 +229,6 @@ var Catalog = (function CatalogClosure() {
         var nameTree = new NameTree(nameTreeRef, xref);
         var names = nameTree.getAll();
         for (var name in names) {
-          if (!names.hasOwnProperty(name)) {
-            continue;
-          }
           dests[name] = fetchDestination(names[name]);
         }
       }
@@ -291,7 +288,7 @@ var Catalog = (function CatalogClosure() {
       var currentLabel = '', currentIndex = 1;
 
       for (var i = 0, ii = this.numPages; i < ii; i++) {
-        if (nums.hasOwnProperty(i)) {
+        if (i in nums) {
           var labelDict = nums[i];
           assert(isDict(labelDict), 'The PageLabel is not a dictionary.');
 
@@ -365,12 +362,9 @@ var Catalog = (function CatalogClosure() {
         var nameTree = new NameTree(nameTreeRef, xref);
         var names = nameTree.getAll();
         for (var name in names) {
-          if (!names.hasOwnProperty(name)) {
-            continue;
-          }
           var fs = new FileSpec(names[name], xref);
           if (!attachments) {
-            attachments = {};
+            attachments = Object.create(null);
           }
           attachments[stringToPDFString(name)] = fs.serializable;
         }
@@ -399,9 +393,6 @@ var Catalog = (function CatalogClosure() {
         var nameTree = new NameTree(obj.getRaw('JavaScript'), xref);
         var names = nameTree.getAll();
         for (var name in names) {
-          if (!names.hasOwnProperty(name)) {
-            continue;
-          }
           // We don't really use the JavaScript right now. This code is
           // defensive so we don't cause errors on document load.
           var jsDict = names[name];
@@ -602,7 +593,7 @@ var XRef = (function XRefClosure() {
   function XRef(stream, password) {
     this.stream = stream;
     this.entries = [];
-    this.xrefstms = {};
+    this.xrefstms = Object.create(null);
     // prepare the XRef cache
     this.cache = [];
     this.password = password;
@@ -1239,7 +1230,7 @@ var NameOrNumberTree = (function NameOrNumberTreeClosure() {
 
   NameOrNumberTree.prototype = {
     getAll: function NameOrNumberTree_getAll() {
-      var dict = {};
+      var dict = Object.create(null);
       if (!this.root) {
         return dict;
       }

src/core/parser.js

@@ -70,7 +70,7 @@ var Parser = (function ParserClosure() {
     this.lexer = lexer;
     this.allowStreams = allowStreams;
     this.xref = xref;
-    this.imageCache = {};
+    this.imageCache = Object.create(null);
     this.refill();
   }
 

src/core/primitives.js

@@ -35,7 +35,7 @@ var Name = (function NameClosure() {
 
   Name.prototype = {};
 
-  var nameCache = {};
+  var nameCache = Object.create(null);
 
   Name.get = function Name_get(name) {
     var nameValue = nameCache[name];
@@ -52,7 +52,7 @@ var Cmd = (function CmdClosure() {
 
   Cmd.prototype = {};
 
-  var cmdCache = {};
+  var cmdCache = Object.create(null);
 
   Cmd.get = function Cmd_get(cmd) {
     var cmdValue = cmdCache[cmd];
@@ -281,7 +281,7 @@ var Ref = (function RefClosure() {
 // This structure stores only one instance of the reference.
 var RefSet = (function RefSetClosure() {
   function RefSet() {
-    this.dict = {};
+    this.dict = Object.create(null);
   }
 
   RefSet.prototype = {

src/core/ps_parser.js

@@ -126,7 +126,7 @@ var PostScriptToken = (function PostScriptTokenClosure() {
     this.value = value;
   }
 
-  var opCache = {};
+  var opCache = Object.create(null);
 
   PostScriptToken.getOperator = function PostScriptToken_getOperator(op) {
     var opValue = opCache[op];

src/display/api.js

@@ -873,7 +873,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
     this.objs = new PDFObjects();
     this.cleanupAfterRender = false;
     this.pendingCleanup = false;
-    this.intentStates = {};
+    this.intentStates = Object.create(null);
     this.destroyed = false;
   }
   PDFPageProxy.prototype = /** @lends PDFPageProxy.prototype */ {
@@ -948,7 +948,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
       var renderingIntent = (params.intent === 'print' ? 'print' : 'display');
 
       if (!this.intentStates[renderingIntent]) {
-        this.intentStates[renderingIntent] = {};
+        this.intentStates[renderingIntent] = Object.create(null);
       }
       var intentState = this.intentStates[renderingIntent];
 
@@ -1040,7 +1040,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
 
       var renderingIntent = 'oplist';
       if (!this.intentStates[renderingIntent]) {
-        this.intentStates[renderingIntent] = {};
+        this.intentStates[renderingIntent] = Object.create(null);
       }
       var intentState = this.intentStates[renderingIntent];
 
@@ -1871,7 +1871,7 @@ var WorkerTransport = (function WorkerTransportClosure() {
  */
 var PDFObjects = (function PDFObjectsClosure() {
   function PDFObjects() {
-    this.objs = {};
+    this.objs = Object.create(null);
   }
 
   PDFObjects.prototype = {
@@ -1962,7 +1962,7 @@ var PDFObjects = (function PDFObjectsClosure() {
     },
 
     clear: function PDFObjects_clear() {
-      this.objs = {};
+      this.objs = Object.create(null);
     }
   };
   return PDFObjects;

src/display/dom_utils.js

@@ -39,7 +39,7 @@ var CustomStyle = (function CustomStyleClosure() {
   // in some versions of IE9 it is critical that ms appear in this list
   // before Moz
   var prefixes = ['ms', 'Moz', 'Webkit', 'O'];
-  var _cache = {};
+  var _cache = Object.create(null);
 
   function CustomStyle() {}
 

src/display/font_loader.js

@@ -340,7 +340,7 @@ Object.defineProperty(FontLoader, 'isSyncFontLoadingSupported', {
 
 var FontFaceObject = (function FontFaceObjectClosure() {
   function FontFaceObject(translatedData) {
-    this.compiledGlyphs = {};
+    this.compiledGlyphs = Object.create(null);
     // importing translated data
     for (var i in translatedData) {
       this[i] = translatedData[i];

src/display/metadata.js

@@ -58,7 +58,7 @@ var Metadata = PDFJS.Metadata = (function MetadataClosure() {
     }
 
     this.metaDocument = meta;
-    this.metadata = {};
+    this.metadata = Object.create(null);
     this.parse();
   }
 

src/display/svg.js

@@ -385,7 +385,7 @@ var SVGGraphics = (function SVGGraphicsClosure() {
     this.pendingEOFill = false;
 
     this.embedFonts = false;
-    this.embeddedFonts = {};
+    this.embeddedFonts = Object.create(null);
     this.cssStyle = null;
   }
 

src/shared/util.js

@@ -1466,7 +1466,7 @@ var StatTimer = (function StatTimerClosure() {
     return str;
   }
   function StatTimer() {
-    this.started = {};
+    this.started = Object.create(null);
     this.times = [];
     this.enabled = true;
   }
@@ -1560,8 +1560,8 @@ function MessageHandler(sourceName, targetName, comObj) {
   this.comObj = comObj;
   this.callbackIndex = 1;
   this.postMessageTransfers = true;
-  var callbacksCapabilities = this.callbacksCapabilities = {};
+  var callbacksCapabilities = this.callbacksCapabilities = Object.create(null);
-  var ah = this.actionHandler = {};
+  var ah = this.actionHandler = Object.create(null);
 
   this._onComObjOnMessage = function messageHandlerComObjOnMessage(event) {
     var data = event.data;

web/debugger.js

@@ -165,7 +165,7 @@ var StepperManager = (function StepperManagerClosure() {
   var stepperDiv = null;
   var stepperControls = null;
   var stepperChooser = null;
-  var breakPoints = {};
+  var breakPoints = Object.create(null);
   return {
     // Properties/functions needed by PDFBug.
     id: 'Stepper',

web/pdf_find_controller.js

@@ -34,7 +34,7 @@ var PDFFindController = (function PDFFindControllerClosure() {
   function PDFFindController(options) {
     this.startedTextExtraction = false;
     this.extractTextPromises = [];
-    this.pendingFindMatches = {};
+    this.pendingFindMatches = Object.create(null);
     this.active = false; // If active, find results will be highlighted.
     this.pageContents = []; // Stores the text for each page.
     this.pageMatches = [];