cc: Add strict layer property change checking and handle bounds changes during paint.

cc/layers/scrollbar_layer_unittest.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/layers/scrollbar_layer.h"
 
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/scrollbar_layer_impl.h"
 #include "cc/quads/solid_color_draw_quad.h"
@@ skipping 121 matching lines @@
                              FakeScrollbarThemePainter::Create(false)
                                  .PassAs<ScrollbarThemePainter>(),
                              FakeWebScrollbarThemeGeometry::Create(true),
                              layer_tree_root->id());
   layer_tree_root->AddChild(content_layer);
   layer_tree_root->AddChild(scrollbar_layer);
 
   layer_tree_root->SetScrollOffset(gfx::Vector2d(10, 20));
   layer_tree_root->SetMaxScrollOffset(gfx::Vector2d(30, 50));
   layer_tree_root->SetBounds(gfx::Size(100, 200));
+  layer_tree_root->PrepareToUpdate();
   content_layer->SetBounds(gfx::Size(100, 200));
+  content_layer->PrepareToUpdate();
 
   scoped_ptr<LayerImpl> layer_impl_tree_root =
       TreeSynchronizer::SynchronizeTrees(layer_tree_root.get(),
                                          scoped_ptr<LayerImpl>(),
                                          host_impl.active_tree());
   TreeSynchronizer::PushProperties(layer_tree_root.get(),
                                    layer_impl_tree_root.get());
 
   ScrollbarLayerImpl* cc_scrollbar_layer =
       static_cast<ScrollbarLayerImpl*>(layer_impl_tree_root->children()[1]);
 
   EXPECT_EQ(10.f, cc_scrollbar_layer->CurrentPos());
   EXPECT_EQ(100, cc_scrollbar_layer->TotalSize());
   EXPECT_EQ(30, cc_scrollbar_layer->Maximum());
 
   layer_tree_root->SetScrollOffset(gfx::Vector2d(100, 200));
   layer_tree_root->SetMaxScrollOffset(gfx::Vector2d(300, 500));
   layer_tree_root->SetBounds(gfx::Size(1000, 2000));
+  layer_tree_root->PrepareToUpdate();
   content_layer->SetBounds(gfx::Size(1000, 2000));
+  content_layer->PrepareToUpdate();
 
   ScrollbarAnimationController* scrollbar_controller =
       layer_impl_tree_root->scrollbar_animation_controller();
   layer_impl_tree_root =
       TreeSynchronizer::SynchronizeTrees(layer_tree_root.get(),
                                          layer_impl_tree_root.Pass(),
                                          host_impl.active_tree());
   TreeSynchronizer::PushProperties(layer_tree_root.get(),
                                    layer_impl_tree_root.get());
   EXPECT_EQ(scrollbar_controller,
@@ skipping 266 matching lines @@
                              FakeWebScrollbarThemeGeometry::Create(true),
                              Layer::PINCH_ZOOM_ROOT_SCROLL_LAYER_ID);
 
   layer_tree_root->AddChild(content_layer);
   layer_tree_root->AddChild(scrollbar_layer_horizontal);
   layer_tree_root->AddChild(scrollbar_layer_vertical);
 
   layer_tree_root->SetScrollOffset(gfx::Vector2d(10, 20));
   layer_tree_root->SetMaxScrollOffset(gfx::Vector2d(30, 50));
   layer_tree_root->SetBounds(gfx::Size(100, 200));
+  layer_tree_root->PrepareToUpdate();
   content_layer->SetBounds(gfx::Size(100, 200));
+  content_layer->PrepareToUpdate();
 
   scoped_ptr<LayerImpl> layer_impl_tree_root =
       TreeSynchronizer::SynchronizeTrees(layer_tree_root.get(),
                                          scoped_ptr<LayerImpl>(),
                                          host_impl.active_tree());
   TreeSynchronizer::PushProperties(layer_tree_root.get(),
                                    layer_impl_tree_root.get());
 
   ScrollbarLayerImpl* pinch_zoom_horizontal =
       static_cast<ScrollbarLayerImpl*>(layer_impl_tree_root->children()[1]);
@@ skipping 17 matching lines @@
   EXPECT_EQ(10.f, pinch_zoom_horizontal->CurrentPos());
   EXPECT_EQ(100, pinch_zoom_horizontal->TotalSize());
   EXPECT_EQ(30, pinch_zoom_horizontal->Maximum());
   EXPECT_EQ(20.f, pinch_zoom_vertical->CurrentPos());
   EXPECT_EQ(200, pinch_zoom_vertical->TotalSize());
   EXPECT_EQ(50, pinch_zoom_vertical->Maximum());
 }
 
 }  // namespace
 }  // namespace cc