Communicate MT changes to impl-only scroll offset animations

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 792 matching lines @@
 
   void AfterTest() override {}
 
  private:
   FakeContentLayerClient client_;
   scoped_refptr<FakePictureLayer> scroll_layer_;
 };
 
 MULTI_THREAD_TEST_F(LayerTreeHostAnimationTestScrollOffsetAnimationTakeover);
 
+// Verifies that an impl-only scroll offset animation gets updated when the
+// scroll offset is adjusted on the main thread.
+class LayerTreeHostAnimationTestScrollOffsetAnimationAdjusted
+    : public LayerTreeHostAnimationTest {
+ public:
+  LayerTreeHostAnimationTestScrollOffsetAnimationAdjusted() {}
+
+  void SetupTree() override {
+    LayerTreeHostAnimationTest::SetupTree();
+
+    scroll_layer_ = FakePictureLayer::Create(&client_);
+    scroll_layer_->SetBounds(gfx::Size(10000, 10000));
+    client_.set_bounds(scroll_layer_->bounds());
+    scroll_layer_->SetScrollOffset(gfx::ScrollOffset(10, 20));
+    layer_tree_host()->root_layer()->AddChild(scroll_layer_);
+
+    AttachPlayersToTimeline();
+    player_child_->AttachElement(scroll_layer_->id());
+  }
+
+  void BeginTest() override { PostSetNeedsCommitToMainThread(); }
+
+  void DidCommit() override {
+    if (layer_tree_host()->source_frame_number() == 1) {
+      // Add an update after the first commit to trigger the animation update
+      // path.
+      ScrollOffsetAnimationUpdate update;
+      update.type_ = ScrollOffsetAnimationUpdate::Type::SCROLL_OFFSET_CHANGED;
+      update.adjustment_ = gfx::Vector2dF(100.f, 100.f);
+      update.element_id_ = scroll_layer_->id();
+      layer_tree_host()->animation_host()->AddScrollOffsetAnimationUpdate(
+          update);
+      EXPECT_TRUE(layer_tree_host()
+                      ->animation_host()
+                      ->HasScrollOffsetAnimationUpdatesForTesting());
+    } else if (layer_tree_host()->source_frame_number() == 2) {
+      // Verify that the update queue is cleared after the update is applied.
+      EXPECT_FALSE(layer_tree_host()
+                       ->animation_host()
+                       ->HasScrollOffsetAnimationUpdatesForTesting());
+    }
+  }
+
+  void BeginCommitOnThread(LayerTreeHostImpl* host_impl) override {
+    // Note that the frame number gets incremented after BeginCommitOnThread but
+    // before WillCommitCompleteOnThread and CommitCompleteOnThread.
+    if (host_impl->sync_tree()->source_frame_number() == 0) {
+      // This happens after the impl-only animation is added in
+      // WillCommitCompleteOnThread.
+      Animation* animation =
+          host_impl->animation_host()
+              ->GetElementAnimationsForElementId(scroll_layer_->id())
+              ->GetAnimation(TargetProperty::SCROLL_OFFSET);
+      ScrollOffsetAnimationCurve* curve =
+          animation->curve()->ToScrollOffsetAnimationCurve();
+
+      // Verifiy the initial and target position before the scroll offset
+      // update from MT.
+      EXPECT_EQ(Animation::RunState::RUNNING, animation->run_state());
+      EXPECT_EQ(gfx::ScrollOffset(10.f, 20.f),
+                curve->GetValue(base::TimeDelta()));
+      EXPECT_EQ(gfx::ScrollOffset(650.f, 750.f), curve->target_value());
+
+      // This is how far the animation is reached until now. It is used to
+      // determine the expecation of initial_positon_ after the update.
+      current_offset_ = curve->GetValue(animation->TrimTimeToCurrentIteration(
+          host_impl->CurrentBeginFrameArgs().frame_time));
+    }
+  }
+
+  void WillCommitCompleteOnThread(LayerTreeHostImpl* host_impl) override {
+    if (host_impl->sync_tree()->source_frame_number() == 0) {
+      host_impl->animation_host()->ImplOnlyScrollAnimationCreate(
+          scroll_layer_->id(), gfx::ScrollOffset(650.f, 750.f),
+          gfx::ScrollOffset(10, 20));
+    }
+  }
+
+  void CommitCompleteOnThread(LayerTreeHostImpl* host_impl) override {
+    if (host_impl->sync_tree()->source_frame_number() == 1) {
+      Animation* animation =
+          host_impl->animation_host()
+              ->GetElementAnimationsForElementId(scroll_layer_->id())
+              ->GetAnimation(TargetProperty::SCROLL_OFFSET);
+      ScrollOffsetAnimationCurve* curve =
+          animation->curve()->ToScrollOffsetAnimationCurve();
+      // Verifiy the initial and target position after the scroll offset
+      // update from MT
+      EXPECT_EQ(Animation::RunState::STARTING, animation->run_state());
+      EXPECT_EQ(
+          ScrollOffsetWithDelta(current_offset_, gfx::Vector2dF(100.f, 100.f)),
+          curve->GetValue(base::TimeDelta()));
+      EXPECT_EQ(gfx::ScrollOffset(750.f, 850.f), curve->target_value());
+
+      EndTest();
+    }
+  }
+
+  void AfterTest() override {}
+
+ private:
+  FakeContentLayerClient client_;
+  gfx::ScrollOffset current_offset_;
+  scoped_refptr<FakePictureLayer> scroll_layer_;
+};
+
+MULTI_THREAD_TEST_F(LayerTreeHostAnimationTestScrollOffsetAnimationAdjusted);
+
 // Verifies that when the main thread removes a scroll animation and sets a new
 // scroll position, the active tree takes on exactly this new scroll position
 // after activation, and the main thread doesn't receive a spurious scroll
 // delta.
 class LayerTreeHostAnimationTestScrollOffsetAnimationRemoval
     : public LayerTreeHostAnimationTest {
  public:
   LayerTreeHostAnimationTestScrollOffsetAnimationRemoval()
       : final_postion_(50.0, 100.0) {}
 
@@ skipping 834 matching lines @@
  private:
   scoped_refptr<Layer> layer_;
   FakeContentLayerClient client_;
 };
 
 MULTI_THREAD_TEST_F(
     LayerTreeHostAnimationTestRebuildPropertyTreesOnAnimationSetNeedsCommit);
 
 }  // namespace
 }  // namespace cc