Move Insert/SignalSyncPoint() to GpuControl

gpu/command_buffer/common/gpu_control.h

Index: gpu/command_buffer/common/gpu_control.h
diff --git a/gpu/command_buffer/common/gpu_control.h b/gpu/command_buffer/common/gpu_control.h
index 503c745b434ff8e1181649e7a10e6a64e9eeafed..b47d85f81198ba1a94d11a28abd64b7394a7ad36 100644
--- a/gpu/command_buffer/common/gpu_control.h
+++ b/gpu/command_buffer/common/gpu_control.h
@@ -5,6 +5,7 @@
 #ifndef GPU_COMMAND_BUFFER_COMMON_GPU_CONTROL_H_
 #define GPU_COMMAND_BUFFER_COMMON_GPU_CONTROL_H_
 
+#include "base/callback.h"
 #include "gpu/command_buffer/common/types.h"
 #include "gpu/gpu_export.h"
 
@@ -33,6 +34,14 @@ class GPU_EXPORT GpuControl {
   // Destroy a gpu memory buffer. The ID must be positive.
   virtual void DestroyGpuMemoryBuffer(int32 id) = 0;
 
+  // Inserts a sync point, returning its ID. Sync point IDs are global and can
+  // be used for cross-context synchronization.
+  virtual uint32 InsertSyncPoint() = 0;
+
+  // Runs |callback| when a sync point is reached or the context is destroyed.

[no sievers, 2013/09/27 18:13:04]

Does it really currently really run it when the context is destroyed?

For context lost, there is actually a test that defines the current behavior:
GLRendererTestSyncPoint.SignalSyncPointOnLostContext, see '// The sync point
shouldn't have happened since the context was lost.'

Although that check if before the context is destroyed.

+  virtual void SignalSyncPoint(uint32 sync_point,
+                               const base::Closure& callback) = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuControl);
 };