cc: Add readback and forced draw states to the Scheduler

cc/scheduler/scheduler.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_SCHEDULER_SCHEDULER_H_
 #define CC_SCHEDULER_SCHEDULER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/scheduler/scheduler_settings.h"
 #include "cc/scheduler/scheduler_state_machine.h"
 #include "cc/trees/layer_tree_host.h"
 
 namespace cc {
 
 class Thread;
 
-struct ScheduledActionDrawAndSwapResult {
-  ScheduledActionDrawAndSwapResult()
-      : did_draw(false),
-        did_swap(false) {}
-  ScheduledActionDrawAndSwapResult(bool did_draw, bool did_swap)
-      : did_draw(did_draw),
-        did_swap(did_swap) {}
+struct DrawSwapReadbackResult {
+  DrawSwapReadbackResult()
+      : did_draw(false), did_swap(false), did_readback(false) {}
+  DrawSwapReadbackResult(bool did_draw, bool did_swap, bool did_readback)
+      : did_draw(did_draw), did_swap(did_swap), did_readback(did_readback) {}
   bool did_draw;
   bool did_swap;
+  bool did_readback;
 };
 
 class SchedulerClient {
  public:
   virtual void SetNeedsBeginFrameOnImplThread(bool enable) = 0;
   virtual void ScheduledActionSendBeginFrameToMainThread() = 0;
-  virtual ScheduledActionDrawAndSwapResult
-  ScheduledActionDrawAndSwapIfPossible() = 0;
-  virtual ScheduledActionDrawAndSwapResult
-  ScheduledActionDrawAndSwapForced() = 0;
+  virtual DrawSwapReadbackResult ScheduledActionDrawAndSwapIfPossible() = 0;
+  virtual DrawSwapReadbackResult ScheduledActionDrawAndSwapForced() = 0;
+  virtual DrawSwapReadbackResult ScheduledActionDrawAndReadback() = 0;
   virtual void ScheduledActionCommit() = 0;
   virtual void ScheduledActionUpdateVisibleTiles() = 0;
   virtual void ScheduledActionActivatePendingTree() = 0;
   virtual void ScheduledActionBeginOutputSurfaceCreation() = 0;
   virtual void ScheduledActionAcquireLayerTexturesForMainThread() = 0;
   virtual void DidAnticipatedDrawTimeChange(base::TimeTicks time) = 0;
   virtual base::TimeDelta DrawDurationEstimate() = 0;
   virtual base::TimeDelta BeginFrameToCommitDurationEstimate() = 0;
   virtual base::TimeDelta CommitToActivateDurationEstimate() = 0;
 
@@ skipping 13 matching lines @@
 
   void SetCanStart();
 
   void SetVisible(bool visible);
   void SetCanDraw(bool can_draw);
   void NotifyReadyToActivate();
 
   void SetNeedsCommit();
 
   // Like SetNeedsCommit(), but ensures a commit will definitely happen even if
-  // we are not visible.
-  void SetNeedsForcedCommit();
+  // we are not visible. Will eventually result in a forced draw internally.
+  void SetNeedsForcedCommitForReadback();
 
   void SetNeedsRedraw();
 
   void SetMainThreadNeedsLayerTextures();
 
-  // Like SetNeedsRedraw(), but ensures the draw will definitely happen even if
-  // we are not visible.
-  void SetNeedsForcedRedraw();
-
   void DidSwapUseIncompleteTile();
 
   void FinishCommit();
   void BeginFrameAbortedByMainThread(bool did_handle);
 
   void DidLoseOutputSurface();
   void DidCreateAndInitializeOutputSurface();
   bool HasInitializedOutputSurface() const {
     return state_machine_.HasInitializedOutputSurface();
   }
@@ skipping 13 matching lines @@
     return state_machine_.AsValue().Pass();
   }
 
  private:
   Scheduler(SchedulerClient* client,
             const SchedulerSettings& scheduler_settings);
 
   void SetupNextBeginFrameIfNeeded();
   void DrawAndSwapIfPossible();
   void DrawAndSwapForced();
+  void DrawAndReadback();
   void ProcessScheduledActions();
 
   const SchedulerSettings settings_;
   SchedulerClient* client_;
 
   base::WeakPtrFactory<Scheduler> weak_factory_;
   bool last_set_needs_begin_frame_;
   bool has_pending_begin_frame_;
   // TODO(brianderson): crbug.com/249806 : Remove safe_to_expect_begin_frame_
   // workaround.
   bool safe_to_expect_begin_frame_;
   BeginFrameArgs last_begin_frame_args_;
 
   SchedulerStateMachine state_machine_;
   bool inside_process_scheduled_actions_;
 
   DISALLOW_COPY_AND_ASSIGN(Scheduler);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_H_