Ensure that the baseTransform is always defined for TilingPatterns

Fixes http://www2.emersonprocess.com/siteadmincenter/PM%20Micro%20Motion%20Documents/High-Pressure-Measurement-WP-001287.pdf#page=3.

src/display/canvas.js

@@ -1558,8 +1558,10 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       var pattern;
       if (IR[0] === 'TilingPattern') {
         var color = IR[1];
+        var baseTransform = this.baseTransform ||
+                            this.ctx.mozCurrentTransform.slice();
         pattern = new TilingPattern(IR, color, this.ctx, this.objs,
-                                    this.commonObjs, this.baseTransform);
+                                    this.commonObjs, baseTransform);
       } else {
         pattern = getShadingPatternFromIR(IR);
       }

test/pdfs/High-Pressure-Measurement-WP-001287.pdf.link

@@ -0,0 +1 @@
+https://web.archive.org/web/20150927202748/http://www2.emersonprocess.com/siteadmincenter/PM%20Micro%20Motion%20Documents/High-Pressure-Measurement-WP-001287.pdf

test/test_manifest.json

@@ -1751,6 +1751,15 @@
        "password": "\u00E6\u00F8\u00E5",
        "about": "The password (æøå) is UTF8 encoded."
     },
+    {  "id": "High-Pressure-Measurement-WP-001287",
+       "file": "pdfs/High-Pressure-Measurement-WP-001287.pdf",
+       "md5": "aeba7e47bbe50cbf08bb8bdff78fec8c",
+       "rounds": 1,
+       "link": true,
+       "firstPage": 3,
+       "lastPage": 3,
+       "type": "eq"
+    },
     { "id": "issue3458.pdf",
       "file": "pdfs/issue3458.pdf",
       "md5": "dab8bd3ad1acfc8dc82a8381a3c8ff94",