CC Animations: Make LayerAnimationController creation optional

ui/compositor/compositor.cc

 // Copyright (c) 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 "ui/compositor/compositor.h"
 
 #include <algorithm>
 #include <deque>
 
 #include "base/bind.h"
@@ skipping 63 matching lines @@
       surface_id_allocator_(context_factory->CreateSurfaceIdAllocator()),
       task_runner_(task_runner),
       vsync_manager_(new CompositorVSyncManager()),
       device_scale_factor_(0.0f),
       last_started_frame_(0),
       last_ended_frame_(0),
       locks_will_time_out_(true),
       compositor_lock_(NULL),
       layer_animator_collection_(this),
       weak_ptr_factory_(this) {
-  root_web_layer_ = cc::Layer::Create();
-
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
 
   cc::LayerTreeSettings settings;
+
+  cc::LayerSettings ui_layer_settings;
+  if (command_line->HasSwitch(
+          switches::kUIEnableCompositorAnimationTimelines)) {
+    settings.hud_layer_settings_.use_compositor_animation_timelines = true;
+    ui_layer_settings.use_compositor_animation_timelines = true;
+  }
+  Layer::SetUILayerSettings(ui_layer_settings);
+
+  root_web_layer_ = cc::Layer::Create(Layer::UILayerSettings());
+
   // When impl-side painting is enabled, this will ensure PictureLayers always
   // can have LCD text, to match the previous behaviour with ContentLayers,
   // where LCD-not-allowed notifications were ignored.
   settings.layers_always_allowed_lcd_text = true;
   settings.renderer_settings.refresh_rate =
       context_factory_->DoesCreateTestContexts() ? kTestRefreshRate
                                                  : kDefaultRefreshRate;
   settings.main_frame_before_activation_enabled = false;
   settings.throttle_frame_production =
       !command_line->HasSwitch(switches::kDisableGpuVsync);
@@ skipping 29 matching lines @@
 
   settings.impl_side_painting = IsUIImplSidePaintingEnabled();
   settings.use_display_lists = IsUISlimmingPaintEnabled();
   settings.use_zero_copy = IsUIZeroCopyEnabled();
   settings.use_one_copy = IsUIOneCopyEnabled();
   settings.use_image_texture_target = context_factory_->GetImageTextureTarget();
   // Note: gathering of pixel refs is only needed when using multiple
   // raster threads.
   settings.gather_pixel_refs = false;
 
-  settings.use_compositor_animation_timelines =
-      command_line->HasSwitch(switches::kUIEnableCompositorAnimationTimelines);
-
   base::TimeTicks before_create = base::TimeTicks::Now();
   host_ = cc::LayerTreeHost::CreateSingleThreaded(
       this, this, context_factory_->GetSharedBitmapManager(),
       context_factory_->GetGpuMemoryBufferManager(),
       context_factory_->GetTaskGraphRunner(), settings, task_runner_, nullptr);
   UMA_HISTOGRAM_TIMES("GPU.CreateBrowserCompositor",
                       base::TimeTicks::Now() - before_create);
   host_->SetRootLayer(root_web_layer_);
   host_->set_surface_id_namespace(surface_id_allocator_->id_namespace());
   host_->SetLayerTreeHostClientReady();
 }
 
 Compositor::~Compositor() {
   TRACE_EVENT0("shutdown", "Compositor::destructor");
 
   CancelCompositorLock();
   DCHECK(!compositor_lock_);
 
   FOR_EACH_OBSERVER(CompositorObserver, observer_list_,
                     OnCompositingShuttingDown(this));
 
   DCHECK(begin_frame_observer_list_.empty());
 
   if (root_layer_)
-    root_layer_->SetCompositor(NULL);
+    root_layer_->ResetCompositor();
 
   // Stop all outstanding draws before telling the ContextFactory to tear
   // down any contexts that the |host_| may rely upon.
   host_.reset();
 
   context_factory_->RemoveCompositor(this);
 }
 
 void Compositor::SetOutputSurface(
     scoped_ptr<cc::OutputSurface> output_surface) {
   host_->SetOutputSurface(output_surface.Pass());
 }
 
 void Compositor::ScheduleDraw() {
   host_->SetNeedsCommit();
 }
 
 void Compositor::SetRootLayer(Layer* root_layer) {
   if (root_layer_ == root_layer)
     return;
   if (root_layer_)
-    root_layer_->SetCompositor(NULL);
+    root_layer_->ResetCompositor();
   root_layer_ = root_layer;
-  if (root_layer_ && !root_layer_->GetCompositor())
-    root_layer_->SetCompositor(this);
   root_web_layer_->RemoveAllChildren();
   if (root_layer_)
-    root_web_layer_->AddChild(root_layer_->cc_layer());
+    root_layer_->SetCompositor(this, root_web_layer_);
 }
 
 void Compositor::SetHostHasTransparentBackground(
     bool host_has_transparent_background) {
   host_->set_has_transparent_background(host_has_transparent_background);
 }
 
 void Compositor::ScheduleFullRedraw() {
   // TODO(enne): Some callers (mac) call this function expecting that it
   // will also commit.  This should probably just redraw the screen
@@ skipping 220 matching lines @@
                     observer_list_,
                     OnCompositingLockStateChanged(this));
 }
 
 void Compositor::CancelCompositorLock() {
   if (compositor_lock_)
     compositor_lock_->CancelLock();
 }
 
 }  // namespace ui