GPUProcessor uses O3D command buffer service to render to a window....

o3d/gpu_plugin/command_buffer_mock.h

Index: o3d/gpu_plugin/command_buffer_mock.h
===================================================================
--- o3d/gpu_plugin/command_buffer_mock.h	(revision 26879)
+++ o3d/gpu_plugin/command_buffer_mock.h	(working copy)
@@ -16,19 +16,24 @@
 class MockCommandBuffer : public CommandBuffer {
  public:
   explicit MockCommandBuffer(NPP npp) : CommandBuffer(npp) {
+    ON_CALL(*this, GetRingBuffer())
+      .WillByDefault(testing::Return(NPObjectPointer<CHRSharedMemory>()));
+    ON_CALL(*this, GetRegisteredObject(testing::_))
+      .WillByDefault(testing::Return(NPObjectPointer<NPObject>()));
   }
 
-  MOCK_METHOD1(Initialize, bool(int32));
+  MOCK_METHOD1(Initialize, bool(int32 size));
   MOCK_METHOD0(GetRingBuffer, NPObjectPointer<CHRSharedMemory>());
   MOCK_METHOD0(GetSize, int32());
-  MOCK_METHOD1(SyncOffsets, int32(int32));
+  MOCK_METHOD1(SyncOffsets, int32(int32 put_offset));
   MOCK_METHOD0(GetGetOffset, int32());
-  MOCK_METHOD1(SetGetOffset, void(int32));
+  MOCK_METHOD1(SetGetOffset, void(int32 get_offset));
   MOCK_METHOD0(GetPutOffset, int32());
-  MOCK_METHOD1(SetPutOffsetChangeCallback, void(Callback0::Type*));
-  MOCK_METHOD1(RegisterObject, int32(NPObjectPointer<NPObject>));
-  MOCK_METHOD2(UnregisterObject, void(NPObjectPointer<NPObject>, int32));
-  MOCK_METHOD0(GetRegisteredObject, NPObjectPointer<NPObject>());
+  MOCK_METHOD1(SetPutOffsetChangeCallback, void(Callback0::Type* callback));
+  MOCK_METHOD1(RegisterObject, int32(NPObjectPointer<NPObject> object));
+  MOCK_METHOD2(UnregisterObject, void(NPObjectPointer<NPObject> object,
+                                      int32 handle));
+  MOCK_METHOD1(GetRegisteredObject, NPObjectPointer<NPObject>(int32 handle));
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockCommandBuffer);