Fix interchange of red and blue content when using rgba_4444_textures

cc/output/renderer_pixeltest.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_loop/message_loop.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/output/gl_renderer.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/picture_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
@@ skipping 2104 matching lines @@
 
   RenderPassList pass_list;
   pass_list.push_back(pass.Pass());
 
   EXPECT_TRUE(this->RunPixelTest(
       &pass_list,
       base::FilePath(FILE_PATH_LITERAL("four_blue_green_checkers.png")),
       ExactPixelComparator(true)));
 }
 
+TEST_F(GLRendererPixelTest, PictureDrawQuadTexture4444) {

[USE eero AT chromium.org, 2014/08/11 14:28:40]

Done.

+  gfx::Size pile_tile_size(1000, 1000);
+  gfx::Rect viewport(this->device_viewport_size_);
+  ResourceFormat texture_format = RGBA_4444;

[USE eero AT chromium.org, 2014/08/11 14:28:40]

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

[enne (OOO), 2014/08/11 19:59:37]

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]

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

+
+  RenderPass::Id id(1, 1);
+  gfx::Transform transform_to_root;
+  scoped_ptr<RenderPass> pass =
+      CreateTestRenderPass(id, viewport, transform_to_root);
+
+  // One viewport-filling blue quad
+  scoped_refptr<FakePicturePileImpl> blue_pile =
+      FakePicturePileImpl::CreateFilledPile(pile_tile_size, viewport.size());
+  SkPaint blue_paint;
+  blue_paint.setColor(SK_ColorBLUE);
+  blue_pile->add_draw_rect_with_paint(viewport, blue_paint);
+  blue_pile->RerecordPile();
+
+  gfx::Transform blue_content_to_target_transform;
+  SharedQuadState* blue_shared_state = CreateTestSharedQuadState(
+      blue_content_to_target_transform, viewport, pass.get());
+
+  PictureDrawQuad* blue_quad = pass->CreateAndAppendDrawQuad<PictureDrawQuad>();
+  blue_quad->SetNew(blue_shared_state,
+                    viewport,
+                    gfx::Rect(),
+                    viewport,
+                    gfx::RectF(0.f, 0.f, 1.f, 1.f),
+                    viewport.size(),
+                    texture_format,
+                    viewport,
+                    1.f,
+                    PicturePileImpl::CreateFromOther(blue_pile));
+
+  RenderPassList pass_list;
+  pass_list.push_back(pass.Pass());
+
+  EXPECT_TRUE(this->RunPixelTest(&pass_list,
+                                 base::FilePath(FILE_PATH_LITERAL("blue.png")),
+                                 ExactPixelComparator(true)));

[USE eero AT chromium.org, 2014/08/11 14:28:40]

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

+}
+
 TYPED_TEST(RendererPixelTest, WrapModeRepeat) {
   gfx::Rect rect(this->device_viewport_size_);
 
   RenderPass::Id id(1, 1);
   scoped_ptr<RenderPass> pass = CreateTestRootRenderPass(id, rect);
 
   SharedQuadState* shared_state =
       CreateTestSharedQuadState(gfx::Transform(), rect, pass.get());
 
   gfx::Rect texture_rect(4, 4);
@@ skipping 46 matching lines @@
   EXPECT_TRUE(this->RunPixelTest(
       &pass_list,
       base::FilePath(FILE_PATH_LITERAL("wrap_mode_repeat.png")),
       FuzzyPixelOffByOneComparator(true)));
 }
 
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace
 }  // namespace cc