Consolidate implementation of ImageBitmapRenderingContext

third_party/WebKit/LayoutTests/fast/canvas/imagebitmap/transferFromImageBitmap-drawImage.html

Index: third_party/WebKit/LayoutTests/fast/canvas/imagebitmap/transferFromImageBitmap-drawImage.html
diff --git a/third_party/WebKit/LayoutTests/fast/canvas/imagebitmap/transferFromImageBitmap-drawImage.html b/third_party/WebKit/LayoutTests/fast/canvas/imagebitmap/transferFromImageBitmap-drawImage.html
index 925ba43815a859f3138f6058a1b874e5dcbc1a94..eb2a3cd86990b54dfa06cb46ce76e075ee7390c3 100644
--- a/third_party/WebKit/LayoutTests/fast/canvas/imagebitmap/transferFromImageBitmap-drawImage.html
+++ b/third_party/WebKit/LayoutTests/fast/canvas/imagebitmap/transferFromImageBitmap-drawImage.html
@@ -15,8 +15,18 @@ function testDrawCanvasWithImageBitamp(image) {
    var dstCanvas = document.createElement('canvas');
    dstCanvas.width = dstCanvas.height = 100;
    var dstCtx = dstCanvas.getContext('bitmaprenderer');
+   assert_true(dstCtx instanceof ImageBitmapRenderingContext);
    dstCtx.transferFromImageBitmap(image);
 
+   // Calling dstCtx.canvas should get the same canvas as the dstCanvas
+   var testCanvas = dstCtx.canvas;
+   assert_equals(dstCanvas.width, testCanvas.width);
+   assert_equals(dstCanvas.height, testCanvas.height);
+
+   // After transferFromImageBitmap, image's width && height should be 0
+   assert_equals(image.width, 0);
+   assert_equals(image.height, 0);
+
    var myCanvas = document.createElement('canvas');
    myCanvas.width = myCanvas.height = 100;
    var myCtx = myCanvas.getContext('2d');