cc : Push layer lists instead of layer tree at commit and activation

cc/trees/layer_tree_host_unittest_scroll.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/location.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 1129 matching lines @@
   LayerTreeHostScrollTestScrollZeroMaxScrollOffset() {}
 
   void BeginTest() override {
     outer_viewport_container_layer_id_ = layer_tree_host()
                                              ->outer_viewport_scroll_layer()
                                              ->scroll_clip_layer()
                                              ->id();
     PostSetNeedsCommitToMainThread();
   }
 
+  void WillCommit() override {

[ajuma, 2016/06/09 15:15:19]

If this is changed to UpdateLayerTreeHost, it will get called before the usual
call to building property trees, and then you won't need the
BuildPropertyTreesForTesting calls below.

[jaydasika, 2016/06/09 16:56:25]

Done.

+    Layer* root = layer_tree_host()->root_layer();
+    Layer* scroll_layer = layer_tree_host()->outer_viewport_scroll_layer();
+    switch (layer_tree_host()->source_frame_number()) {
+      case 0:
+        scroll_layer->SetScrollClipLayerId(outer_viewport_container_layer_id_);
+        // Set max_scroll_offset = (100, 100).
+        scroll_layer->SetBounds(gfx::Size(root->bounds().width() + 100,
+                                          root->bounds().height() + 100));
+        root->layer_tree_host()->BuildPropertyTreesForTesting();
+        break;
+      case 1:
+        // Set max_scroll_offset = (0, 0).
+        scroll_layer->SetBounds(root->bounds());
+        root->layer_tree_host()->BuildPropertyTreesForTesting();
+        break;
+      case 2:
+        // Set max_scroll_offset = (-100, -100).
+        scroll_layer->SetBounds(gfx::Size());
+        root->layer_tree_host()->BuildPropertyTreesForTesting();
+        break;
+    }
+  }
+
   void DrawLayersOnThread(LayerTreeHostImpl* impl) override {
-    LayerImpl* root = impl->active_tree()->root_layer();
     LayerImpl* scroll_layer = impl->OuterViewportScrollLayer();
-    scroll_layer->SetScrollClipLayer(outer_viewport_container_layer_id_);
-
-    // Set max_scroll_offset = (100, 100).
-    scroll_layer->SetBounds(
-        gfx::Size(root->bounds().width() + 100, root->bounds().height() + 100));
-    impl->active_tree()->property_trees()->needs_rebuild = true;
-    impl->active_tree()->BuildLayerListAndPropertyTreesForTesting();
 
     ScrollTree& scroll_tree =
         impl->active_tree()->property_trees()->scroll_tree;
     ScrollNode* scroll_node =
         scroll_tree.Node(scroll_layer->scroll_tree_index());
-
     InputHandler::ScrollStatus status =
         impl->TryScroll(gfx::PointF(0.0f, 1.0f), InputHandler::TOUCHSCREEN,
                         scroll_tree, scroll_node);
-
-    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
-    EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
-              status.main_thread_scrolling_reasons);
-
-    // Set max_scroll_offset = (0, 0).
-    scroll_layer->SetBounds(root->bounds());
-    impl->active_tree()->property_trees()->needs_rebuild = true;
-    impl->active_tree()->BuildLayerListAndPropertyTreesForTesting();
-    scroll_tree = impl->active_tree()->property_trees()->scroll_tree;
-    scroll_node = scroll_tree.Node(scroll_layer->scroll_tree_index());
-    status = impl->TryScroll(gfx::PointF(0.0f, 1.0f), InputHandler::TOUCHSCREEN,
-                             scroll_tree, scroll_node);
-    EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
-    EXPECT_EQ(MainThreadScrollingReason::kNotScrollable,
-              status.main_thread_scrolling_reasons);
-
-    // Set max_scroll_offset = (-100, -100).
-    scroll_layer->SetBounds(gfx::Size());
-    impl->active_tree()->property_trees()->needs_rebuild = true;
-    impl->active_tree()->BuildLayerListAndPropertyTreesForTesting();
-    scroll_tree = impl->active_tree()->property_trees()->scroll_tree;
-    scroll_node = scroll_tree.Node(scroll_layer->scroll_tree_index());
-    status = impl->TryScroll(gfx::PointF(0.0f, 1.0f), InputHandler::TOUCHSCREEN,
-                             scroll_tree, scroll_node);
-    EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
-    EXPECT_EQ(MainThreadScrollingReason::kNotScrollable,
-              status.main_thread_scrolling_reasons);
-
-    EndTest();
+    switch (impl->active_tree()->source_frame_number()) {
+      case 0:
+        EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
+        EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
+                  status.main_thread_scrolling_reasons);
+        PostSetNeedsCommitToMainThread();
+        break;
+      case 1:
+        EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
+        EXPECT_EQ(MainThreadScrollingReason::kNotScrollable,
+                  status.main_thread_scrolling_reasons);
+        PostSetNeedsCommitToMainThread();
+        break;
+      case 2:
+        EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
+        EXPECT_EQ(MainThreadScrollingReason::kNotScrollable,
+                  status.main_thread_scrolling_reasons);
+        EndTest();
+        break;
+    }
   }
 
   void AfterTest() override {}
 
  private:
   int outer_viewport_container_layer_id_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(
     LayerTreeHostScrollTestScrollZeroMaxScrollOffset);
@@ skipping 301 matching lines @@
   RunTest(CompositorMode::THREADED, false);
 }
 
 TEST_F(LayerTreeHostScrollTestLayerStructureChange, ScrollDestroyWholeTree) {
   scroll_destroy_whole_tree_ = true;
   RunTest(CompositorMode::THREADED, false);
 }
 
 }  // namespace
 }  // namespace cc