cc: Fix cc_unittests when main frame before activation is enabled.

cc/trees/layer_tree_host_unittest_animation.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 <stdint.h>
 
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/animation_host.h"
@@ skipping 844 matching lines @@
         player_child_->RemoveAnimation(animation->id());
         scroll_layer_->SetScrollOffset(final_postion_);
         break;
       }
       default:
         EXPECT_EQ(final_postion_, scroll_layer_->scroll_offset());
     }
   }
 
   void BeginCommitOnThread(LayerTreeHostImpl* host_impl) override {
-    host_impl->BlockNotifyReadyToActivateForTesting(true);
+    host_impl->BlockNotifyReadyToActivateForTesting(
+        ShouldBlockActivation(host_impl));
   }
 
   void WillBeginImplFrameOnThread(LayerTreeHostImpl* host_impl,
                                   const BeginFrameArgs& args) override {
-    if (!host_impl->pending_tree())
-      return;
-
-    if (!host_impl->active_tree()->root_layer()) {
-      host_impl->BlockNotifyReadyToActivateForTesting(false);
-      return;
-    }
-
-    scoped_refptr<AnimationTimeline> timeline_impl =
-        host_impl->animation_host()->GetTimelineById(timeline_id_);
-    scoped_refptr<AnimationPlayer> player_impl =
-        timeline_impl->GetPlayerById(player_child_id_);
-
-    LayerImpl* scroll_layer_impl =
-        host_impl->active_tree()->LayerById(scroll_layer_->id());
-    Animation* animation = player_impl->element_animations()
-                               ->GetAnimation(TargetProperty::SCROLL_OFFSET);
-
-    if (!animation || animation->run_state() != Animation::RUNNING) {
-      host_impl->BlockNotifyReadyToActivateForTesting(false);
-      return;
-    }
-
-    // Block activation until the running animation has a chance to produce a
-    // scroll delta.
-    gfx::Vector2dF scroll_delta = ScrollDelta(scroll_layer_impl);
-    if (scroll_delta.x() < 1.f || scroll_delta.y() < 1.f)
-      return;
-
-    host_impl->BlockNotifyReadyToActivateForTesting(false);
+    host_impl->BlockNotifyReadyToActivateForTesting(
+        ShouldBlockActivation(host_impl));
   }
 
   void WillActivateTreeOnThread(LayerTreeHostImpl* host_impl) override {
     if (host_impl->pending_tree()->source_frame_number() != 1)
       return;
     LayerImpl* scroll_layer_impl =
         host_impl->pending_tree()->LayerById(scroll_layer_->id());
     EXPECT_EQ(final_postion_, scroll_layer_impl->CurrentScrollOffset());
   }
 
   void DidActivateTreeOnThread(LayerTreeHostImpl* host_impl) override {
     if (host_impl->active_tree()->source_frame_number() != 1)
       return;
     LayerImpl* scroll_layer_impl =
         host_impl->active_tree()->LayerById(scroll_layer_->id());
     EXPECT_EQ(final_postion_, scroll_layer_impl->CurrentScrollOffset());
     EndTest();
   }
 
   void AfterTest() override {
     EXPECT_EQ(final_postion_, scroll_layer_->scroll_offset());
   }
 
  private:
+  bool ShouldBlockActivation(LayerTreeHostImpl* host_impl) {
+    if (!host_impl->pending_tree())
+      return false;
+
+    if (!host_impl->active_tree()->root_layer())
+      return false;
+
+    scoped_refptr<AnimationTimeline> timeline_impl =
+        host_impl->animation_host()->GetTimelineById(timeline_id_);
+    scoped_refptr<AnimationPlayer> player_impl =
+        timeline_impl->GetPlayerById(player_child_id_);
+
+    LayerImpl* scroll_layer_impl =
+        host_impl->active_tree()->LayerById(scroll_layer_->id());
+    Animation* animation = player_impl->element_animations()->GetAnimation(
+        TargetProperty::SCROLL_OFFSET);
+
+    if (!animation || animation->run_state() != Animation::RUNNING)
+      return false;
+
+    // Block activation until the running animation has a chance to produce a
+    // scroll delta.
+    gfx::Vector2dF scroll_delta = ScrollDelta(scroll_layer_impl);
+    if (scroll_delta.x() > 0.f || scroll_delta.y() > 0.f)

[enne (OOO), 2016/05/13 01:26:02]

This is the only real change in the patch, right?  It's a little hard to see
with the function moving.  I'm not sure I understand what's happening with and
without the command line flag wrt to this scroll delta.

[sunnyps, 2016/05/14 00:41:19]

This isn't the substantive change of this CL. The big change is that
BeginCommitOnImplThread blocks activation based on the same conditions as
WillBeginImplFrameOnThread. So we don't keep blocking activation on every
commit.

+      return false;
+
+    return true;
+  }
+
   FakeContentLayerClient client_;
   scoped_refptr<FakePictureLayer> scroll_layer_;
   const gfx::ScrollOffset final_postion_;
 };
 
 MULTI_THREAD_TEST_F(LayerTreeHostAnimationTestScrollOffsetAnimationRemoval);
 
 // When animations are simultaneously added to an existing layer and to a new
 // layer, they should start at the same time, even when there's already a
 // running animation on the existing layer.
@@ skipping 723 matching lines @@
  private:
   scoped_refptr<Layer> layer_;
   FakeContentLayerClient client_;
 };
 
 MULTI_THREAD_TEST_F(
     LayerTreeHostAnimationTestRebuildPropertyTreesOnAnimationSetNeedsCommit);
 
 }  // namespace
 }  // namespace cc