cc: Implement unified BeginFrame on aura

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 7c4a706a5175cbec50cec49b392bd105670633b9..cc53f5e5fcb3a4046fb742ae7bb1389c1af8490c 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -13,6 +13,7 @@
 #include "base/observer_list.h"
 #include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/surfaces/surface_sequence.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_single_thread_client.h"
@@ -53,7 +54,6 @@ struct Mailbox;
 namespace ui {
 
 class Compositor;
-class CompositorVSyncManager;
 class Layer;
 class Reflector;
 class Texture;
@@ -128,6 +128,14 @@ class COMPOSITOR_EXPORT CompositorLock
   DISALLOW_COPY_AND_ASSIGN(CompositorLock);
 };
 
+// This class observes BeginFrame notification from LayerTreeHost.
+class COMPOSITOR_EXPORT CompositorBeginFrameObserver {
+ public:
+  virtual ~CompositorBeginFrameObserver() {}
+
+  virtual void OnSendBeginFrame(const cc::BeginFrameArgs& args) = 0;
+};
+
 // Compositor object to take care of GPU painting.
 // A Browser compositor object is responsible for generating the final
 // displayable form of pixels comprising a single widget's contents. It draws an
@@ -201,12 +209,17 @@ class COMPOSITOR_EXPORT Compositor
   // Gets the visibility of the underlying compositor.
   bool IsVisible();
 
+  // The "authoritative" vsync interval, if provided, will override interval
+  // reported from 3D context. This is typically the value reported by a more
+  // reliable source, e.g, the platform display configuration.
+  // In the particular case of ChromeOS -- this is the value queried through
+  // XRandR, which is more reliable than the value queried through the 3D
+  // context.
+  void SetAuthoritativeVSyncInterval(const base::TimeDelta& interval);
+
   // Returns the widget for this compositor.
   gfx::AcceleratedWidget widget() const { return widget_; }
 
-  // Returns the vsync manager for this compositor.
-  scoped_refptr<CompositorVSyncManager> vsync_manager() const;
-
   // Returns the main thread task runner this compositor uses. Users of the
   // compositor generally shouldn't use this.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner() const {
@@ -223,6 +236,11 @@ class COMPOSITOR_EXPORT Compositor
   void RemoveAnimationObserver(CompositorAnimationObserver* observer);
   bool HasAnimationObserver(const CompositorAnimationObserver* observer) const;
 
+  void AddBeginFrameObserver(
+      CompositorBeginFrameObserver* observer,
+      const cc::BeginFrameArgs& last_begin_frame_args_sent_to_observer);
+  void RemoveBeginFrameObserver(CompositorBeginFrameObserver* observer);
+
   // Creates a compositor lock. Returns NULL if it is not possible to lock at
   // this time (i.e. we're waiting to complete a previous unlock).
   scoped_refptr<CompositorLock> GetCompositorLock();
@@ -261,6 +279,7 @@ class COMPOSITOR_EXPORT Compositor
   void DidCommitAndDrawFrame() override;
   void DidCompleteSwapBuffers() override;
   void DidCompletePageScaleAnimation() override {}
+  void SendBeginFramesToChildren(const cc::BeginFrameArgs& args) override;
 
   // cc::LayerTreeHostSingleThreadClient implementation.
   void DidPostSwapBuffers() override;
@@ -283,6 +302,7 @@ class COMPOSITOR_EXPORT Compositor
  private:
   friend class base::RefCounted<Compositor>;
   friend class CompositorLock;
+  friend class CompositorTestAPI;

[brianderson, 2015/03/06 20:36:59]

Instead of adding a CompositorTestAPI as a friend, can you:
1) Make this section protected.
2) Create a TestCompositor (to replace CompositorTestAPI) that inherits from
ui::Compositor in compositor_unittest.cc.
3) Delete compositor_test_api.h and compositor_test_api.cc

It's a pattern that's used often in Chrome. It helps avoid putting test-specific
code in the production code.

 
   // Called by CompositorLock.
   void UnlockCompositor();
@@ -290,6 +310,9 @@ class COMPOSITOR_EXPORT Compositor
   // Called to release any pending CompositorLock
   void CancelCompositorLock();
 
+  // Request scheduling of next BeginFrame to LayerTreeHost.
+  void SetChildrenNeedBeginFrames(bool need_begin_frame);
+
   gfx::Size size_;
 
   ui::ContextFactory* context_factory_;
@@ -299,6 +322,7 @@ class COMPOSITOR_EXPORT Compositor
 
   ObserverList<CompositorObserver, true> observer_list_;
   ObserverList<CompositorAnimationObserver> animation_observer_list_;
+  ObserverList<CompositorBeginFrameObserver> begin_frame_observer_list_;
 
   gfx::AcceleratedWidget widget_;
   scoped_ptr<cc::SurfaceIdAllocator> surface_id_allocator_;
@@ -306,9 +330,6 @@ class COMPOSITOR_EXPORT Compositor
   scoped_ptr<cc::LayerTreeHost> host_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
-  // The manager of vsync parameters for this compositor.
-  scoped_refptr<CompositorVSyncManager> vsync_manager_;
-
   // The device scale factor of the monitor that this compositor is compositing
   // layers on.
   float device_scale_factor_;
@@ -322,6 +343,9 @@ class COMPOSITOR_EXPORT Compositor
 
   LayerAnimatorCollection layer_animator_collection_;
 
+  // Used to send to any new CompositorBeginFrameObserver immediately.
+  cc::BeginFrameArgs missed_begin_frame_args_;
+
   base::WeakPtrFactory<Compositor> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);