Added method to synchronize command buffers within GpuControl.

gpu/command_buffer/client/gpu_control.h

 // Copyright 2014 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 GPU_COMMAND_BUFFER_CLIENT_GPU_CONTROL_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GPU_CONTROL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 68 matching lines @@
   // Sets a lock this will be held on every callback from the GPU
   // implementation. This lock must be set and must be held on every call into
   // the GPU implementation if it is to be used from multiple threads. This
   // may not be supported with all implementations.
   virtual void SetLock(base::Lock*) = 0;
 
   // Returns true if the channel to the Gpu is lost. When true, all contexts
   // should be considered as lost.
   virtual bool IsGpuChannelLost() = 0;
 
+  // When this function returns it ensures all previously flushed work is
+  // visible by the service. This command does this by sending a synchronous
+  // IPC. Note just because the work is visible to the server does not mean
+  // that it has been processed. This is only relevant for out of process
+  // services and will be treated as a NOP for in process command buffers.
+  virtual void EnsureWorkVisible() = 0;
+
   // The namespace and command buffer ID forms a unique pair for all existing
   // GpuControl (on client) and matches for the corresponding command buffer
   // (on server) in a single server process. The extra command buffer data can
   // be used for extra identification purposes. One usage is to store some
   // extra field to identify unverified sync tokens for the implementation of
   // the CanWaitUnverifiedSyncToken() function.
   virtual CommandBufferNamespace GetNamespaceID() const = 0;
   virtual uint64_t GetCommandBufferID() const = 0;
   virtual int32_t GetExtraCommandBufferData() const = 0;
 
@@ skipping 19 matching lines @@
   // be enqueued first so does not need to be flushed.
   virtual bool CanWaitUnverifiedSyncToken(const SyncToken* sync_token) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuControl);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GPU_CONTROL_H_