Replace Util.extendObj by Object.assign

src/core/operator_list.js

@@ -13,9 +13,7 @@
  * limitations under the License.
  */
 
-import {
+import { ImageKind, OPS } from '../shared/util';
-  ImageKind, OPS, Util
-} from '../shared/util';
 
 var QueueOptimizer = (function QueueOptimizerClosure() {
   function addState(parentState, pattern, checkFn, iterateFn, processFn) {
@@ -612,7 +610,7 @@ var OperatorList = (function OperatorListClosure() {
     },
 
     addOpList(opList) {
-      Util.extendObj(this.dependencies, opList.dependencies);
+      Object.assign(this.dependencies, opList.dependencies);
       for (var i = 0, ii = opList.length; i < ii; i++) {
         this.addOp(opList.fnArray[i], opList.argsArray[i]);
       }

src/display/api.js

@@ -18,7 +18,7 @@ import {
   assert, createPromiseCapability, getVerbosityLevel, info, InvalidPDFException,
   isArrayBuffer, isSameOrigin, MissingPDFException, NativeImageDecoding,
   PasswordException, setVerbosityLevel, shadow, stringToBytes,
-  UnexpectedResponseException, UnknownErrorException, unreachable, Util, warn
+  UnexpectedResponseException, UnknownErrorException, unreachable, warn
 } from '../shared/util';
 import {
   DOMCanvasFactory, DOMCMapReaderFactory, DummyStatTimer, loadScript,
@@ -1074,7 +1074,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
               resolve(textContent);
               return;
             }
-            Util.extendObj(textContent.styles, value.styles);
+            Object.assign(textContent.styles, value.styles);
             textContent.items.push(...value.items);
             pump();
           }, reject);

src/display/text_layer.js

@@ -578,10 +578,9 @@ var renderTextLayer = (function renderTextLayerClosure() {
               return;
             }
 
-            Util.extendObj(styleCache, value.styles);
+            Object.assign(styleCache, value.styles);
             this._processItems(value.items, styleCache);
             pump();
-
           }, capability.reject);
         };
 

src/shared/compatibility.js

@@ -109,6 +109,15 @@ const hasDOM = typeof window === 'object' && typeof document === 'object';
   require('core-js/fn/array/includes');
 })();
 
+// Provides support for Object.assign in legacy browsers.
+// Support: IE
+(function checkObjectAssign() {
+  if (Object.assign) {
+    return;
+  }
+  require('core-js/fn/object/assign');
+})();
+
 // Provides support for Math.log2 in legacy browsers.
 // Support: IE, Chrome<38
 (function checkMathLog2() {

src/shared/util.js

@@ -886,12 +886,6 @@ var Util = (function UtilClosure() {
     return (lowerCase ? romanStr.toLowerCase() : romanStr);
   };
 
-  Util.extendObj = function extendObj(obj1, obj2) {
-    for (var key in obj2) {
-      obj1[key] = obj2[key];
-    }
-  };
-
   Util.inherit = function Util_inherit(sub, base, prototype) {
     sub.prototype = Object.create(base.prototype);
     sub.prototype.constructor = sub;