Remove the command buffer method glGetImageivCHROMIUM.

ppapi/proxy/ppapi_command_buffer_proxy.cc

Index: ppapi/proxy/ppapi_command_buffer_proxy.cc
diff --git a/ppapi/proxy/ppapi_command_buffer_proxy.cc b/ppapi/proxy/ppapi_command_buffer_proxy.cc
index b7c526486ef352b287c170bc696056a003b1d3f7..77ef28217f98a9e8316a1eac4ed92494a61e62b6 100644
--- a/ppapi/proxy/ppapi_command_buffer_proxy.cc
+++ b/ppapi/proxy/ppapi_command_buffer_proxy.cc
@@ -262,11 +262,6 @@ int32_t PpapiCommandBufferProxy::CreateGpuMemoryBufferImage(
   return -1;
 }
 
-int32_t PpapiCommandBufferProxy::GetImageGpuMemoryBufferId(unsigned image_id) {
-  NOTREACHED();
-  return -1;
-}
-
 bool PpapiCommandBufferProxy::Send(IPC::Message* msg) {
   DCHECK(last_state_.error == gpu::error::kNoError);