Fix interchange of red and blue content when using rgba_4444_textures

Fix interchange of red and blue content when using rgba_4444_textures

Content is swizzled when texture format has different component order
than expected format by platform. RGBA_4444 implies to use 4444 bits and
does not affect component order. So, no need to swizzle contents.

BUG=399634
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=289266

[USE eero AT chromium.org, 2014-08-11 14:28:41]

As Sarath is out of office for a while, I took over his issue
(https://codereview.chromium.org/434963002) and uploaded a fixed patch set here.

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest.cc
File cc/output/renderer_pixeltest.cc (right):

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest...
cc/output/renderer_pixeltest.cc:2125: TEST_F(GLRendererPixelTest,
PictureDrawQuadTexture4444) {
On 2014/08/08 18:16:17, enne wrote on
https://codereview.chromium.org/434963002/diff/20001/cc/output/renderer_pixel...:
> This isn't relevant for the software renderer, so probably should be
> TEST_F(GLRendererPixelTest, PictureDrawQuadTexture4444).

Done.

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest...
cc/output/renderer_pixeltest.cc:2128: ResourceFormat texture_format = RGBA_4444;
On 2014/08/08 18:16:17, enne wrote on
https://codereview.chromium.org/434963002/diff/20001/cc/output/renderer_pixel...:
> Do all platforms support this format? Should there be a check and an early
out?

No idea. I did not find any relevant function to be used for testing the
support. Is there any?

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest...
cc/output/renderer_pixeltest.cc:2164: ExactPixelComparator(true)));
On 2014/08/08 18:16:17, enne wrote on
https://codereview.chromium.org/434963002/diff/20001/cc/output/renderer_pixel...:
> Use an exact comparator.

Done. For that to work, I changed the blue components of the blue.png image from
254 to 255.

[enne (OOO), 2014-08-11 19:59:38]

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest.cc
File cc/output/renderer_pixeltest.cc (right):

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest...
cc/output/renderer_pixeltest.cc:2128: ResourceFormat texture_format = RGBA_4444;
On 2014/08/11 14:28:40, e_hakkinen wrote:
> On 2014/08/08 18:16:17, enne wrote on
>
https://codereview.chromium.org/434963002/diff/20001/cc/output/renderer_pixel...:
> > Do all platforms support this format? Should there be a check and an early
> out?
> 
> No idea. I did not find any relevant function to be used for testing the
> support. Is there any?

Really the question is if Mesa supports this.  I assume this test fails if you
don't make the code change in platform_color?

[USE eero AT chromium.org, 2014-08-12 09:26:11]

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest.cc
File cc/output/renderer_pixeltest.cc (right):

https://codereview.chromium.org/460563003/diff/1/cc/output/renderer_pixeltest...
cc/output/renderer_pixeltest.cc:2128: ResourceFormat texture_format = RGBA_4444;
On 2014/08/11 19:59:37, enne wrote:
> Really the question is if Mesa supports this.

Unit tests seem to be using osmesa GL implementation by default (based on code)
and that is what I used for testing this pixel test (based on vlog messages,
too), so yes, Mesa supports this.

> I assume this test fails if you don't make the code change in platform_color?

Yes, the test fails if the cc/resources/platform_color.h header file is not
patched.

[enne (OOO), 2014-08-12 17:41:41]

Thanks, lgtm.

[USE eero AT chromium.org, 2014-08-13 07:45:36]

The CQ bit was checked by e.hakkinen@samsung.com

[commit-bot: I haz the power, 2014-08-13 07:47:39]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/e.hakkinen@samsung.com/460563003/1

[commit-bot: I haz the power, 2014-08-13 11:27:35]

Change committed as 289266