Expose GpuMemoryBufferId through glGetImageivCHROMIUM.

gpu/command_buffer/service/in_process_command_buffer.cc

Index: gpu/command_buffer/service/in_process_command_buffer.cc
diff --git a/gpu/command_buffer/service/in_process_command_buffer.cc b/gpu/command_buffer/service/in_process_command_buffer.cc
index 5184f76df5d56c65378a45282046d3633527aee5..ad390a937986099b237619505d8246ef7c6c4769 100644
--- a/gpu/command_buffer/service/in_process_command_buffer.cc
+++ b/gpu/command_buffer/service/in_process_command_buffer.cc
@@ -682,6 +682,9 @@ int32_t InProcessCommandBuffer::CreateImage(ClientBuffer buffer,
   DCHECK(gpu::IsImageFormatCompatibleWithGpuMemoryBufferFormat(
       internalformat, gpu_memory_buffer->GetFormat()));
 
+  DCHECK(image_gmb_ids_map_.find(new_id) == image_gmb_ids_map_.end());
+  image_gmb_ids_map_[new_id] = gpu_memory_buffer->GetId().id;
+
   // This handle is owned by the GPU thread and must be passed to it or it
   // will leak. In otherwords, do not early out on error between here and the
   // queuing of the CreateImage task below.
@@ -786,6 +789,10 @@ void InProcessCommandBuffer::CreateImageOnGpuThread(
 void InProcessCommandBuffer::DestroyImage(int32_t id) {
   CheckSequencedThread();
 
+  auto it = image_gmb_ids_map_.find(id);
+  if (it != image_gmb_ids_map_.end())
+    image_gmb_ids_map_.erase(it);
+
   QueueTask(base::Bind(&InProcessCommandBuffer::DestroyImageOnGpuThread,
                        base::Unretained(this),
                        id));
@@ -824,6 +831,14 @@ int32_t InProcessCommandBuffer::CreateGpuMemoryBufferImage(
   return CreateImage(buffer->AsClientBuffer(), width, height, internalformat);
 }
 
+int32_t InProcessCommandBuffer::GetImageGpuMemoryBufferId(unsigned image_id) {
+  CheckSequencedThread();
+  auto it = image_gmb_ids_map_.find(image_id);
+  if (it != image_gmb_ids_map_.end())
+    return it->second;
+  return -1;
+}
+
 void InProcessCommandBuffer::FenceSyncReleaseOnGpuThread(uint64_t release) {
   DCHECK(!sync_point_client_->client_state()->IsFenceSyncReleased(release));
   gles2::MailboxManager* mailbox_manager =