Expose GpuMemoryBufferId through glGetImageivCHROMIUM.

gpu/command_buffer/tests/gl_manager.h

Index: gpu/command_buffer/tests/gl_manager.h
diff --git a/gpu/command_buffer/tests/gl_manager.h b/gpu/command_buffer/tests/gl_manager.h
index eb61cc73b7c7bb6e2f71dc3e5c512e403fd4f0da..e4fdaafa186878ad77e27a4810ab1cead2e15820 100644
--- a/gpu/command_buffer/tests/gl_manager.h
+++ b/gpu/command_buffer/tests/gl_manager.h
@@ -132,6 +132,7 @@ class GLManager : private GpuControl {
                                      size_t height,
                                      unsigned internalformat,
                                      unsigned usage) override;
+  int32_t GetImageGpuMemoryBufferId(unsigned image_id) override;
   void SignalQuery(uint32_t query, const base::Closure& callback) override;
   void SetLock(base::Lock*) override;
   void EnsureWorkVisible() override;
@@ -180,6 +181,9 @@ class GLManager : private GpuControl {
 
   bool use_iosurface_memory_buffers_ = false;
 
+  // A map from image id to GpuMemoryBuffer id.
+  std::map<int32_t, int32_t> image_gmb_ids_map_;
+
   // Used on Android to virtualize GL for all contexts.
   static int use_count_;
   static scoped_refptr<gl::GLShareGroup>* base_share_group_;