I created a GIF image that has a single frame with color at frame 0.  THis is followed by "count-down" image frames, all of which have no color (they are black, white, and gray only, viz., they have no color).  Basic idea attached ...

Deleted: count-down-color-test-image-frames.png 176 KB

	count-down-color-test-image-frames.png 176 KB View Download

Created a GIF image using the above idea of width: 315px, height: 236px, and 74 frames in total, where only frame 0 has color. I converted the GIF to APNG, and WEBP animated (these test resources attached).

Deleted: count-down-color-test.gif 213 KB

	count-down-color-test.gif 213 KB View Download

Deleted: count-down-color-test.png 467 KB

	count-down-color-test.png 467 KB View Download

Deleted: count-down-color-test.webp 261 KB

	count-down-color-test.webp 261 KB View Download

Wrote a layout test: see https://codereview.chromium.org/2728193004

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/427dfb952160b6402103f5db70a0e3dc6c5c500d

commit 427dfb952160b6402103f5db70a0e3dc6c5c500d
Author: noel <noel@chromium.org>
Date: Sat Mar 11 03:40:37 2017

Add canvas.drawImage test for animated image types

canvas.drawImage() for animated images should draw the initial frame
(or poster frame) of the animated image, per spec. Add a layout test
that covers GIF, APNG, and WEBP animated images, ensure the test can
also be run manually in any browser [1].

[1] Manual testing: the test uses <canvas> to read the image pixels,
so serve the test page from a local web server (Chrome's same origin
policy prevents the pixel read otherwise). If you have python handy,
a script can be used:

#!/bin/bash -
# Simple python server: run in the local directory you want to serve
# then load http://localhost:8888 in your browser.
python -m SimpleHTTPServer 8888

BUG= 698487 

Review-Url: https://codereview.chromium.org/2728193004
Cr-Commit-Position: refs/heads/master@{#456273}

[add] https://crrev.com/427dfb952160b6402103f5db70a0e3dc6c5c500d/third_party/WebKit/LayoutTests/fast/canvas/canvas-drawImage-animated-images-expected.txt
[add] https://crrev.com/427dfb952160b6402103f5db70a0e3dc6c5c500d/third_party/WebKit/LayoutTests/fast/canvas/canvas-drawImage-animated-images.html
[add] https://crrev.com/427dfb952160b6402103f5db70a0e3dc6c5c500d/third_party/WebKit/LayoutTests/images/resources/count-down-color-test.gif
[add] https://crrev.com/427dfb952160b6402103f5db70a0e3dc6c5c500d/third_party/WebKit/LayoutTests/images/resources/count-down-color-test.png
[add] https://crrev.com/427dfb952160b6402103f5db70a0e3dc6c5c500d/third_party/WebKit/LayoutTests/images/resources/count-down-color-test.webp