Make the canvas in race layout test smaller

third_party/WebKit/LayoutTests/fast/canvas/script-tests/canvas-toBlob-toDataURL-race.js

 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
 }
 
 var numToBlobCalls = 9;
 var numToDataURLCalls = 3;
 var testImages = [];
 var canvasCtxs = [];
 
 // Create an original canvas with content
 var canvas = document.createElement("canvas");
 var ctx = canvas.getContext("2d");
 ctx.fillStyle = "#EE21AF";
-ctx.fillRect(0, 0, 2500, 1750);
+ctx.fillRect(0, 0, 250, 150);
 
 function testIfAllImagesAreCorrect()
 {
     // All resultant images should be the same as both async and main threads use the same image encoder
     var imageMatched = true;
-    var firstImageData = canvasCtxs[0].getImageData(0, 0, 2500, 1750).data;
+    var firstImageData = canvasCtxs[0].getImageData(0, 0, 250, 150).data;
     for (var i = 1; i < (numToBlobCalls + numToDataURLCalls); i++) 
     {
-        var nextImageData = canvasCtxs[i].getImageData(0, 0, 2500, 1750).data;
+        var nextImageData = canvasCtxs[i].getImageData(0, 0, 250, 150).data;
         for (var k = 0; k < firstImageData.length; k++) 
         {
             if (firstImageData[k]!=nextImageData[k]) 
             {
                 imageMatched = false;
                 break;
             }
         } 
         if (!imageMatched) 
             break;
@@ skipping 16 matching lines @@
 }
 
 function createTestCase(i)
 {
     var canvas_test = document.createElement("canvas");
     var ctx_test = canvas_test.getContext("2d");
     canvasCtxs[i] = ctx_test;
 
     var newImg = new Image();
     newImg.onload = function() {
-        ctx_test.drawImage(newImg, 0, 0, 2500, 1750);
+        ctx_test.drawImage(newImg, 0, 0, 250, 150);
         onCanvasDrawCompleted(ctx_test);
     }    
     testImages[i] = newImg;
 }
 
 for (var i = 0; i < (numToBlobCalls + numToDataURLCalls); i++) 
 {
     createTestCase(i);
 }