cc: Add pixel tests for transfer function shaders

cc/test/pixel_test.cc

Index: cc/test/pixel_test.cc
diff --git a/cc/test/pixel_test.cc b/cc/test/pixel_test.cc
index 2731c76dba0d08e365fc92fd1be2b9d718664857..6abb7968f5c466e644f006956ec68f36e6ae8e51 100644
--- a/cc/test/pixel_test.cc
+++ b/cc/test/pixel_test.cc
@@ -92,6 +92,43 @@ bool PixelTest::RunPixelTestWithReadbackTargetAndArea(
   return PixelsMatchReference(ref_file, comparator);
 }
 
+bool PixelTest::RunPixelTest(RenderPassList* pass_list,
+                             std::vector<SkColor>* ref_pixels,
+                             const PixelComparator& comparator) {
+  base::RunLoop run_loop;
+  RenderPass* target = pass_list->back().get();
+
+  std::unique_ptr<CopyOutputRequest> request =
+      CopyOutputRequest::CreateBitmapRequest(
+          base::Bind(&PixelTest::ReadbackResult, base::Unretained(this),
+                     run_loop.QuitClosure()));
+  target->copy_requests.push_back(std::move(request));
+
+  if (software_renderer_) {
+    software_renderer_->SetDisablePictureQuadImageFiltering(
+        disable_picture_quad_image_filtering_);
+  }
+
+  renderer_->DecideRenderPassAllocationsForFrame(*pass_list);
+  float device_scale_factor = 1.f;
+  renderer_->DrawFrame(pass_list, device_scale_factor, device_viewport_size_);
+
+  // Wait for the readback to complete.
+  if (output_surface_->context_provider())
+    output_surface_->context_provider()->ContextGL()->Finish();
+  run_loop.Run();
+
+  // Need to wrap |ref_pixels| in a SkBitmap.
+  DCHECK_EQ(ref_pixels->size(), static_cast<size_t>(result_bitmap_->width() *
+                                                    result_bitmap_->height()));
+  SkBitmap ref_pixels_bitmap;
+  ref_pixels_bitmap.installPixels(
+      SkImageInfo::MakeN32Premul(result_bitmap_->width(),
+                                 result_bitmap_->height()),
+      ref_pixels->data(), result_bitmap_->width() * sizeof(SkColor));
+  return comparator.Compare(*result_bitmap_, ref_pixels_bitmap);
+}
+
 void PixelTest::ReadbackResult(base::Closure quit_run_loop,
                                std::unique_ptr<CopyOutputResult> result) {
   ASSERT_TRUE(result->HasBitmap());