Revert of cc: Make scheduling be driven by vsync for android webview.

cc/scheduler/scheduler_state_machine.h

Index: cc/scheduler/scheduler_state_machine.h
diff --git a/cc/scheduler/scheduler_state_machine.h b/cc/scheduler/scheduler_state_machine.h
index 39f9faa23d1713ada6b7189753912053da658577..f568665d293903f8124e611db4fb10bc8d4042e7 100644
--- a/cc/scheduler/scheduler_state_machine.h
+++ b/cc/scheduler/scheduler_state_machine.h
@@ -50,10 +50,10 @@
   };
   static const char* OutputSurfaceStateToString(OutputSurfaceState state);
 
-  // Note: BeginImplFrameState does not cycle through these states in a fixed
-  // order on all platforms. It's up to the scheduler to set these correctly.
-  // TODO(sunnyps): Rename the states to IDLE, ANIMATE, WAITING_FOR_DEADLINE and
-  // DRAW.
+  // Note: BeginImplFrameState will always cycle through all the states in
+  // order. Whether or not it actually waits or draws, it will at least try to
+  // wait in BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME and try to draw in
+  // BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE
   enum BeginImplFrameState {
     BEGIN_IMPL_FRAME_STATE_IDLE,
     BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
@@ -63,7 +63,6 @@
   static const char* BeginImplFrameStateToString(BeginImplFrameState state);
 
   enum BeginImplFrameDeadlineMode {
-    BEGIN_IMPL_FRAME_DEADLINE_MODE_NONE,
     BEGIN_IMPL_FRAME_DEADLINE_MODE_IMMEDIATE,
     BEGIN_IMPL_FRAME_DEADLINE_MODE_REGULAR,
     BEGIN_IMPL_FRAME_DEADLINE_MODE_LATE,
@@ -112,7 +111,6 @@
     ACTION_DRAW_AND_SWAP_ABORT,
     ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
     ACTION_PREPARE_TILES,
-    ACTION_INVALIDATE_OUTPUT_SURFACE,
   };
   static const char* ActionToString(Action action);
 
@@ -125,15 +123,18 @@
   // Indicates whether the impl thread needs a BeginImplFrame callback in order
   // to make progress.
   bool BeginFrameNeeded() const;
+
+  // Indicates that we need to independently poll for new state and actions
+  // because we can't expect a BeginImplFrame. This is mostly used to avoid
+  // drawing repeat frames with the synchronous compositor without dropping
+  // necessary actions on the floor.
+  bool ShouldPollForAnticipatedDrawTriggers() const;
 
   // Indicates that the system has entered and left a BeginImplFrame callback.
   // The scheduler will not draw more than once in a given BeginImplFrame
   // callback nor send more than one BeginMainFrame message.
   void OnBeginImplFrame();
   void OnBeginImplFrameDeadlinePending();
-  // Indicates that the scheduler has entered the draw phase. The scheduler
-  // will not draw more than once in a single draw phase.
-  // TODO(sunnyps): Rename OnBeginImplFrameDeadline to OnDraw or similar.
   void OnBeginImplFrameDeadline();
   void OnBeginImplFrameIdle();
   BeginImplFrameState begin_impl_frame_state() const {
@@ -144,6 +145,15 @@
   // If the main thread didn't manage to produce a new frame in time for the
   // impl thread to draw, it is in a high latency mode.
   bool MainThreadIsInHighLatencyMode() const;
+
+  // PollForAnticipatedDrawTriggers is used by the synchronous compositor to
+  // avoid requesting BeginImplFrames when we won't actually draw but still
+  // need to advance our state at vsync intervals.
+  void DidEnterPollForAnticipatedDrawTriggers();
+  void DidLeavePollForAnticipatedDrawTriggers();
+  bool inside_poll_for_anticipated_draw_triggers() const {
+    return inside_poll_for_anticipated_draw_triggers_;
+  }
 
   // Indicates whether the LayerTreeHostImpl is visible.
   void SetVisible(bool visible);
@@ -236,6 +246,8 @@
 
   // True if we need to abort draws to make forward progress.
   bool PendingDrawsShouldBeAborted() const;
+
+  bool SupportsProactiveBeginFrame() const;
 
   void SetContinuousPainting(bool continuous_painting) {
     continuous_painting_ = continuous_painting;
@@ -271,16 +283,13 @@
   bool ShouldSendBeginMainFrame() const;
   bool ShouldCommit() const;
   bool ShouldPrepareTiles() const;
-  bool ShouldInvalidateOutputSurface() const;
-
-  void UpdateStateOnAnimate();
-  void UpdateStateOnSendBeginMainFrame();
+
+  void AdvanceCurrentFrameNumber();
+
   void UpdateStateOnCommit(bool commit_had_no_updates);
   void UpdateStateOnActivation();
   void UpdateStateOnDraw(bool did_request_swap);
-  void UpdateStateOnBeginOutputSurfaceCreation();
   void UpdateStateOnPrepareTiles();
-  void UpdateStateOnInvalidateOutputSurface();
 
   const SchedulerSettings settings_;
 
@@ -296,14 +305,13 @@
   int last_frame_number_swap_performed_;
   int last_frame_number_swap_requested_;
   int last_frame_number_begin_main_frame_sent_;
-  int last_frame_number_invalidate_output_surface_performed_;
 
   // These are used to ensure that an action only happens once per frame,
   // deadline, etc.
   bool animate_funnel_;
+  bool perform_swap_funnel_;
   bool request_swap_funnel_;
   bool send_begin_main_frame_funnel_;
-  bool invalidate_output_surface_funnel_;
   // prepare_tiles_funnel_ is "filled" each time PrepareTiles is called
   // and "drained" on each BeginImplFrame. If the funnel gets too full,
   // we start throttling ACTION_PREPARE_TILES such that we average one
@@ -317,6 +325,7 @@
   bool needs_animate_;
   bool needs_prepare_tiles_;
   bool needs_commit_;
+  bool inside_poll_for_anticipated_draw_triggers_;
   bool visible_;
   bool can_start_;
   bool can_draw_;
@@ -332,8 +341,6 @@
   bool defer_commits_;
   bool last_commit_had_no_updates_;
   bool wait_for_active_tree_ready_to_draw_;
-  bool did_request_swap_in_last_frame_;
-  bool did_perform_swap_in_last_draw_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);