Move 2d.getImageData.* in canvas_api to wpt

[chromium-wpt-export-bot]

Move 2d.getImageData.* from canvas_api to wpt.

Bug: 1071659

Change-Id: I444088c44eb6f93d4800175deef05f99bfc8e98c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2159913
Commit-Queue: Yi Xu <yiyix@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#763137}

[wpt-pr-bot]

The review process for this patch is being conducted in the Chromium project.

[foolip]

The update-built step has failed on Taskcluster with this error:

--- a/2dcontext/pixel-manipulation/2d.imageData.get.rounding.html
+++ b/2dcontext/pixel-manipulation/2d.imageData.get.rounding.html
@@ -26,18 +26,18 @@ function testDimensions(sx, sy, sw, sh, width, height)
     _assert(imageData.height == height, "imageData.height == height");
 }
 
-testDimensions(   0,  0,   20,  10,     20, 10);
+testDimensions(0, 0, 20, 10, 20, 10);
 
-testDimensions(  .1, .2,   20,  10,     20, 10);
-testDimensions(  .9, .8,   20,  10,     20, 10);
+testDimensions(.1, .2, 20, 10, 20, 10);
+testDimensions(.9, .8, 20, 10, 20, 10);
 
-testDimensions(   0,  0, 20.9, 10.9,     20, 10);
-testDimensions(   0,  0, 20.1, 10.1,     20, 10);
+testDimensions(0, 0, 20.9, 10.9, 20, 10);
+testDimensions(0, 0, 20.1, 10.1, 20, 10);
 
-testDimensions(  -1, -1,   20,  10,     20, 10);
+testDimensions(-1, -1, 20, 10, 20, 10);
 
-testDimensions(-1.1,  0,   20,  10,     20, 10);
-testDimensions(-1.9,  0,   20,  10,     20, 10);
+testDimensions(-1.1, 0, 20, 10, 20, 10);
+testDimensions(-1.9,  0, 20, 10, 20, 10);

[foolip]

Since it's just whitespace changes I've applied them and pushed.

[foolip]

wpt-firefox-nightly-results-without-changes is still running, but this is blocking another Chromium export so I'm going to admin merge it now.