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

cc/trees/layer_tree_host.cc

 // Copyright 2011 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 <algorithm>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 79 matching lines @@
       debug_state_(settings.initial_debug_state),
       overdraw_bottom_height_(0.f),
       device_scale_factor_(1.f),
       visible_(true),
       page_scale_factor_(1.f),
       min_page_scale_factor_(1.f),
       max_page_scale_factor_(1.f),
       trigger_idle_updates_(true),
       background_color_(SK_ColorWHITE),
       has_transparent_background_(false),
-      partial_texture_update_requests_(0) {
+      partial_texture_update_requests_(0),
+      in_paint_layer_contents_(false) {
   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   s_num_layer_tree_instances++;
 
   rendering_stats_instrumentation_->set_record_rendering_stats(
       debug_state_.RecordRenderingStats());
 }
 
 bool LayerTreeHost::Initialize(scoped_ptr<Thread> impl_thread) {
   if (impl_thread)
@@ skipping 817 matching lines @@
       settings_.minimum_occlusion_tracking_size);
 
   PrioritizeTextures(render_surface_layer_list,
                      occlusion_tracker.overdraw_metrics());
 
   // TODO(egraether): Use RenderingStatsInstrumentation in Layer::update()
   RenderingStats stats;
   RenderingStats* stats_ptr =
       debug_state_.RecordRenderingStats() ? &stats : NULL;
 
+  in_paint_layer_contents_ = true;
+
   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list);
   for (LayerIteratorType it =
            LayerIteratorType::Begin(&render_surface_layer_list);
        it != end;
        ++it) {
     occlusion_tracker.EnterLayer(it);
 
     if (it.represents_target_render_surface()) {
       DCHECK(it->render_surface()->draw_opacity() ||
              it->render_surface()->draw_opacity_is_animating());
       need_more_updates |= PaintMasksForRenderSurface(*it, queue, stats_ptr);
     } else if (it.represents_itself()) {
       DCHECK(!it->bounds().IsEmpty());
       it->Update(queue, &occlusion_tracker, stats_ptr);
       need_more_updates |= it->NeedMoreUpdates();
     }
 
     occlusion_tracker.LeaveLayer(it);
   }
 
+  in_paint_layer_contents_ = false;
+
   rendering_stats_instrumentation_->AddStats(stats);
 
   occlusion_tracker.overdraw_metrics()->RecordMetrics(this);
 
   return need_more_updates;
 }
 
 void LayerTreeHost::ApplyScrollAndScale(const ScrollAndScaleSet& info) {
   if (!root_layer_)
     return;
@@ skipping 112 matching lines @@
     bool start_ready_animations = true;
     (*iter).second->UpdateState(start_ready_animations, NULL);
   }
 }
 
 skia::RefPtr<SkPicture> LayerTreeHost::CapturePicture() {
   return proxy_->CapturePicture();
 }
 
 }  // namespace cc