cc: Give ownership of render passes to the renderer when drawing a frame.

cc/layer_tree_host_impl.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/layer_tree_host_impl.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
@@ skipping 798 matching lines @@
     m_client->setNeedsCommitOnImplThread();
 }
 
 void LayerTreeHostImpl::onVSyncParametersChanged(double monotonicTimebase, double intervalInSeconds)
 {
     base::TimeTicks timebase = base::TimeTicks::FromInternalValue(monotonicTimebase * base::Time::kMicrosecondsPerSecond);
     base::TimeDelta interval = base::TimeDelta::FromMicroseconds(intervalInSeconds * base::Time::kMicrosecondsPerSecond);
     m_client->onVSyncParametersChanged(timebase, interval);
 }
 
-void LayerTreeHostImpl::drawLayers(const FrameData& frame)
+void LayerTreeHostImpl::drawLayers(FrameData& frame)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::drawLayers");
     DCHECK(canDraw());
     DCHECK(!frame.renderPasses.empty());
 
     // FIXME: use the frame begin time from the overall compositor scheduler.
     // This value is currently inaccessible because it is up in Chromium's
     // RenderWidget.
     m_fpsCounter->markBeginningOfFrame(base::TimeTicks::Now());
 
     if (m_debugState.showHudRects())
         m_debugRectHistory->saveDebugRectsForCurrentFrame(m_rootLayerImpl.get(), *frame.renderSurfaceLayerList, frame.occludingScreenSpaceRects, frame.nonOccludingScreenSpaceRects, m_debugState);
 
     // Because the contents of the HUD depend on everything else in the frame, the contents
     // of its texture are updated as the last thing before the frame is drawn.
     if (m_hudLayerImpl)
         m_hudLayerImpl->updateHudTexture(m_resourceProvider.get());
 
     m_renderer->drawFrame(frame.renderPasses, frame.renderPassesById);
 
-    // Once a RenderPass has been drawn, its damage should be cleared in
-    // case the RenderPass will be reused next frame.
-    for (unsigned int i = 0; i < frame.renderPasses.size(); i++)
-        frame.renderPasses[i]->damage_rect = gfx::RectF();
+    // The render passes should be consumed by the renderer.
+    DCHECK(frame.renderPasses.empty());
+    DCHECK(frame.renderPassesById.empty());
 
     // The next frame should start by assuming nothing has changed, and changes are noted as they occur.
     for (unsigned int i = 0; i < frame.renderSurfaceLayerList->size(); i++)
         (*frame.renderSurfaceLayerList)[i]->renderSurface()->damageTracker()->didDrawDamagedArea();
     m_rootLayerImpl->resetAllChangeTrackingForSubtree();
 }
 
 void LayerTreeHostImpl::didDrawAllLayers(const FrameData& frame)
 {
     for (size_t i = 0; i < frame.willDrawLayers.size(); ++i)
@@ skipping 778 matching lines @@
     ScrollbarAnimationController* scrollbarController = layer->scrollbarAnimationController();
     double monotonicTime = (time - base::TimeTicks()).InSecondsF();
     if (scrollbarController && scrollbarController->animate(monotonicTime))
         m_client->setNeedsRedrawOnImplThread();
 
     for (size_t i = 0; i < layer->children().size(); ++i)
         animateScrollbarsRecursive(layer->children()[i], time);
 }
 
 }  // namespace cc