cc/blimp: Eliminate Layer updates for common cases.

cc/blimp/compositor_state_deserializer_unittest.cc

 // Copyright 2016 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 "compositor_state_deserializer.h"
 
 #include "base/run_loop.h"
 #include "cc/animation/animation_host.h"
 #include "cc/blimp/client_picture_cache.h"
 #include "cc/blimp/compositor_proto_state.h"
@@ skipping 484 matching lines @@
               scroll_layer2->id()));
   EXPECT_EQ(client_scroll_layer2->ScrollLayerId(),
             compositor_state_deserializer_
                 ->GetLayerForEngineId(scroll_layer2->ScrollLayerId())
                 ->id());
   EXPECT_EQ(client_scroll_layer2->orientation(), scroll_layer2->orientation());
 }
 
 TEST_F(CompositorStateDeserializerTest, PictureLayer) {
   scoped_refptr<Layer> root_layer = Layer::Create();
+  root_layer->SetBounds(gfx::Size(10, 10));
+  root_layer->SetIsDrawable(true);
   layer_tree_host_remote_->GetLayerTree()->SetRootLayer(root_layer);
 
   gfx::Size layer_size = gfx::Size(5, 5);
 
   gfx::PointF offset(2.f, 3.f);
   SkPictureRecorder recorder;
   sk_sp<SkCanvas> canvas;
   SkPaint red_paint;
   red_paint.setColor(SK_ColorRED);
   canvas = sk_ref_sp(recorder.beginRecording(SkRect::MakeXYWH(
       offset.x(), offset.y(), layer_size.width(), layer_size.height())));
   canvas->translate(offset.x(), offset.y());
   canvas->drawRectCoords(0.f, 0.f, 4.f, 4.f, red_paint);
   sk_sp<SkPicture> test_picture = recorder.finishRecordingAsPicture();
 
   DisplayItemListSettings settings;
   settings.use_cached_picture = false;
   scoped_refptr<DisplayItemList> display_list =
       DisplayItemList::Create(settings);
   const gfx::Rect visual_rect(0, 0, 42, 42);
   display_list->CreateAndAppendDrawingItem<DrawingDisplayItem>(visual_rect,
                                                                test_picture);
   display_list->Finalize();
   FakeContentLayerClient content_client(display_list, gfx::Rect(layer_size));
 
   scoped_refptr<PictureLayer> picture_layer =
       PictureLayer::Create(&content_client);
   picture_layer->SetBounds(layer_size);
+  picture_layer->SetIsDrawable(true);
   root_layer->AddChild(picture_layer);
 
   // Synchronize State and verify.
   base::RunLoop().RunUntilIdle();
   VerifyTreesAreIdentical();
 
   // Verify PictureLayer.
   PictureLayer* client_picture_layer = static_cast<PictureLayer*>(
       compositor_state_deserializer_->GetLayerForEngineId(picture_layer->id()));
   scoped_refptr<DisplayItemList> client_display_list =
       client_picture_layer->client()->PaintContentsToDisplayList(
           ContentLayerClient::PaintingControlSetting::PAINTING_BEHAVIOR_NORMAL);
   EXPECT_TRUE(AreDisplayListDrawingResultsSame(
       gfx::Rect(layer_size), display_list.get(), client_display_list.get()));
 
   // Now attach new layer with the same DisplayList.
   scoped_refptr<PictureLayer> picture_layer2 =
       PictureLayer::Create(&content_client);
-  picture_layer->SetBounds(layer_size);
+  picture_layer2->SetBounds(layer_size);
+  picture_layer2->SetIsDrawable(true);
   root_layer->AddChild(picture_layer2);
 
   // Synchronize State and verify.
   base::RunLoop().RunUntilIdle();
   VerifyTreesAreIdentical();
 
   // Verify PictureLayer2.
   PictureLayer* client_picture_layer2 = static_cast<PictureLayer*>(
       compositor_state_deserializer_->GetLayerForEngineId(
           picture_layer2->id()));
   scoped_refptr<DisplayItemList> client_display_list2 =
       client_picture_layer2->client()->PaintContentsToDisplayList(
           ContentLayerClient::PaintingControlSetting::PAINTING_BEHAVIOR_NORMAL);
   EXPECT_TRUE(AreDisplayListDrawingResultsSame(
       gfx::Rect(layer_size), display_list.get(), client_display_list2.get()));
 }
 
 }  // namespace
 }  // namespace cc