cc: Make LayerTreeHostImpl::SwapBuffers not virtual.

cc/trees/layer_tree_host_unittest_damage.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 "cc/trees/layer_tree_host.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/time/time.h"
@@ skipping 131 matching lines @@
 
   int draw_count_;
   FakeContentLayerClient client_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestSetViewportSize);
 
 class LayerTreeHostDamageTestNoDamageDoesNotSwap
     : public LayerTreeHostDamageTest {
   void BeginTest() override {
-    expect_swap_and_succeed_ = 0;
-    did_swaps_ = 0;
-    did_swap_and_succeed_ = 0;
     PostSetNeedsCommitToMainThread();
   }
 
   void SetupTree() override {
     scoped_refptr<FakePictureLayer> root = FakePictureLayer::Create(&client_);
     root->SetBounds(gfx::Size(10, 10));
 
     // Most of the layer isn't visible.
     content_ = FakePictureLayer::Create(&client_);
     content_->SetBounds(gfx::Size(2000, 100));
     root->AddChild(content_);
 
     layer_tree_host()->SetRootLayer(root);
     LayerTreeHostDamageTest::SetupTree();
     client_.set_bounds(root->bounds());
   }
 
   DrawResult PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
                                    LayerTreeHostImpl::FrameData* frame_data,
                                    DrawResult draw_result) override {
     EXPECT_EQ(DRAW_SUCCESS, draw_result);
 
     int source_frame = host_impl->active_tree()->source_frame_number();
     switch (source_frame) {
       case 0:
         // The first frame has damage, so we should draw and swap.
-        ++expect_swap_and_succeed_;
+        EXPECT_FALSE(frame_data->has_no_damage);
+        ++expect_swap_;
         break;
       case 1:
         // The second frame has no damage, so we should not draw and swap.
+        EXPECT_TRUE(frame_data->has_no_damage);
         break;
       case 2:
         // The third frame has damage again, so we should draw and swap.
-        ++expect_swap_and_succeed_;
+        EXPECT_FALSE(frame_data->has_no_damage);
+        ++expect_swap_;
         break;
       case 3:
         // The fourth frame has no visible damage, so we should not draw and
         // swap.
+        EXPECT_TRUE(frame_data->has_no_damage);
         EndTest();
         break;
     }
     return draw_result;
   }
 
-  void SwapBuffersOnThread(LayerTreeHostImpl* host_impl, bool result) override {
-    ++did_swaps_;
-    if (result)

[danakj, 2016/07/13 21:50:18]

This just isn't called if result was false. So we stop tracking the old
"did_swaps_", and EXPECT on the has_no_damage at prepare-to-draw time instead.

-      ++did_swap_and_succeed_;
-    EXPECT_EQ(expect_swap_and_succeed_, did_swap_and_succeed_);
+  void SwapBuffersCompleteOnThread() override {
+    ++did_swap_;
+    EXPECT_EQ(expect_swap_, did_swap_);
   }
 
   void DidCommit() override {
     int next_frame = layer_tree_host()->source_frame_number();
     switch (next_frame) {
       case 1:
         layer_tree_host()->SetNeedsCommit();
         break;
       case 2:
         // Cause visible damage.
         content_->SetNeedsDisplayRect(
             gfx::Rect(layer_tree_host()->device_viewport_size()));
         break;
       case 3:
         // Cause non-visible damage.
         content_->SetNeedsDisplayRect(gfx::Rect(1990, 1990, 10, 10));
         layer_tree_host()->SetNeedsCommit();
         break;
     }
   }
 
   void AfterTest() override {
-    EXPECT_EQ(4, did_swaps_);
-    EXPECT_EQ(2, expect_swap_and_succeed_);
-    EXPECT_EQ(expect_swap_and_succeed_, did_swap_and_succeed_);
+    EXPECT_EQ(2, expect_swap_);
+    EXPECT_EQ(expect_swap_, did_swap_);
   }
 
   FakeContentLayerClient client_;
   scoped_refptr<FakePictureLayer> content_;
-  int expect_swap_and_succeed_;
-  int did_swaps_;
-  int did_swap_and_succeed_;
+  int expect_swap_ = 0;
+  int did_swap_ = 0;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestNoDamageDoesNotSwap);
 
 class LayerTreeHostDamageTestForcedFullDamage : public LayerTreeHostDamageTest {
   void BeginTest() override { PostSetNeedsCommitToMainThread(); }
 
   void SetupTree() override {
     root_ = FakePictureLayer::Create(&client_);
     child_ = FakePictureLayer::Create(&client_);
@@ skipping 157 matching lines @@
         break;
       case 3:
         // The fourth frame should damage the scrollbars.
         EXPECT_TRUE(root_damage.Contains(gfx::Rect(300, 300, 10, 100)));
         EndTest();
         break;
     }
     return draw_result;
   }
 
-  void SwapBuffersOnThread(LayerTreeHostImpl* host_impl, bool result) override {
+  void DrawLayersOnThread(LayerTreeHostImpl* host_impl) override {
     ++did_swaps_;
-    EXPECT_TRUE(result);
     LayerImpl* scroll_layer =
         host_impl->active_tree()->LayerById(content_layer_->id());
     switch (did_swaps_) {
       case 1:
         // Test that modifying the position of the content layer (not
         // scrolling) won't damage the scrollbar.
         MainThreadTaskRunner()->PostTask(
             FROM_HERE, base::Bind(&LayerTreeHostDamageTestScrollbarDoesDamage::
                                       ModifyContentLayerPosition,
                                   base::Unretained(this)));
@@ skipping 64 matching lines @@
         EXPECT_EQ(1, frame);
         EXPECT_FALSE(root_damage.Intersects(gfx::Rect(300, 300, 10, 100)));
         break;
       default:
         NOTREACHED();
         break;
     }
     return draw_result;
   }
 
-  void SwapBuffersOnThread(LayerTreeHostImpl* host_impl, bool result) override {
+  void DrawLayersOnThread(LayerTreeHostImpl* host_impl) override {
     ++did_swaps_;
-    EXPECT_TRUE(result);
     LayerImpl* scroll_layer =
         host_impl->active_tree()->LayerById(content_layer_->id());
     switch (did_swaps_) {
       case 1:
         // Scroll on the thread.  This should damage the scrollbar for the
         // next draw on the thread.
         scroll_layer->ScrollBy(gfx::Vector2dF(10.f, 10.f));
         host_impl->SetNeedsRedraw();
         break;
       case 2:
@@ skipping 12 matching lines @@
 
   void AfterTest() override { EXPECT_EQ(3, did_swaps_); }
 
   int did_swaps_;
 };
 
 MULTI_THREAD_TEST_F(LayerTreeHostDamageTestScrollbarCommitDoesNoDamage);
 
 }  // namespace
 }  // namespace cc