cc: Make PrepareToDraw return an enum for why it aborts

cc/trees/layer_tree_host_impl.h

 // 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.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 12 matching lines @@
 #include "cc/input/top_controls_manager_client.h"
 #include "cc/layers/layer_lists.h"
 #include "cc/layers/render_pass_sink.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/output/managed_memory_policy.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/output/renderer.h"
 #include "cc/quads/render_pass.h"
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/tile_manager.h"
+#include "cc/scheduler/draw_swap_readback_result.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/rect.h"
 
 namespace cc {
 
 class CompletionEvent;
 class CompositorFrameMetadata;
 class DebugRectHistory;
 class FrameRateCounter;
@@ skipping 129 matching lines @@
   void UpdateBackgroundAnimateTicking(bool should_background_tick);
   void DidAnimateScrollOffset();
   void SetViewportDamage(const gfx::Rect& damage_rect);
 
   virtual void ManageTiles();
 
   // Returns false if problems occured preparing the frame, and we should try
   // to avoid displaying the frame. If PrepareToDraw is called, DidDrawAllLayers
   // must also be called, regardless of whether DrawLayers is called between the
   // two.
-  virtual bool PrepareToDraw(FrameData* frame,
-                             const gfx::Rect& damage_rect);
+  virtual DrawSwapReadbackResult::DrawResult PrepareToDraw(
+      FrameData* frame,
+      const gfx::Rect& damage_rect);
   virtual void DrawLayers(FrameData* frame, base::TimeTicks frame_begin_time);
   // Must be called if and only if PrepareToDraw was called.
   void DidDrawAllLayers(const FrameData& frame);
 
   const LayerTreeSettings& settings() const { return settings_; }
 
   // Evict all textures by enforcing a memory policy with an allocation of 0.
   void EvictTexturesForTesting();
 
   // When blocking, this prevents client_->NotifyReadyToActivate() from being
@@ skipping 280 matching lines @@
       const gfx::PointF& viewport_point,
       const gfx::Vector2dF& viewport_delta);
 
   void UpdateMaxScrollOffset();
   void TrackDamageForAllSurfaces(
       LayerImpl* root_draw_layer,
       const LayerImplList& render_surface_layer_list);
 
   void UpdateTileManagerMemoryPolicy(const ManagedMemoryPolicy& policy);
 
-  // Returns false if the frame should not be displayed. This function should
-  // only be called from PrepareToDraw, as DidDrawAllLayers must be called
-  // if this helper function is called.
-  bool CalculateRenderPasses(FrameData* frame);
+  // This function should only be called from PrepareToDraw, as DidDrawAllLayers
+  // must be called if this helper function is called.  Returns DID_DRAW if
+  // the frame should be drawn.
+  DrawSwapReadbackResult::DrawResult CalculateRenderPasses(FrameData* frame);
 
   void SendReleaseResourcesRecursive(LayerImpl* current);
   bool EnsureRenderSurfaceLayerList();
   void ClearCurrentlyScrollingLayer();
 
   bool HandleMouseOverScrollbar(LayerImpl* layer_impl,
                                 const gfx::PointF& device_viewport_point);
 
   void AnimateScrollbarsRecursive(LayerImpl* layer,
                                   base::TimeTicks time);
@@ skipping 154 matching lines @@
   int id_;
 
   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_