Convert some pixel tests in fast/canvas into ref tests.

LayoutTests/fast/canvas/drawImage.html

Index: LayoutTests/fast/canvas/drawImage.html
diff --git a/LayoutTests/fast/canvas/drawImage.html b/LayoutTests/fast/canvas/drawImage.html
index ce94c27f5a5e89f9296f0eed439332c4371f239b..edc2a5401c232b865153d60602a5543f7d61cf7f 100644
--- a/LayoutTests/fast/canvas/drawImage.html
+++ b/LayoutTests/fast/canvas/drawImage.html
@@ -1,10 +1,7 @@
-If this renders correctly you should see one big friendly green square.
+<p>If this renders correctly you should see one big friendly green square.</p>
 <canvas id="canvas" width="200" height="200" ></canvas>
 <canvas id="canvas2" width="200" height="200" style="display:none" ></canvas>
 <script>
-if (window.testRunner)
-  testRunner.dumpAsTextWithPixelResults();
-
 var canvas = document.getElementById("canvas");
 var canvas2 = document.getElementById("canvas2");
 var context = canvas.getContext("2d");
@@ -13,5 +10,6 @@ context2.fillStyle = 'red';
 context2.fillRect(0,0,200,200);
 context2.fillStyle = 'green';
 context2.fillRect(50,50,100,100);
+context.imageSmoothingEnabled = false;
 context.drawImage(canvas2, 50, 50, 100, 100, 0, 0, 200, 200);
-</script>
+</script>