Make lost context and error message callbacks on GpuControl go to client

mojo/gles2/command_buffer_client_impl.cc

Index: mojo/gles2/command_buffer_client_impl.cc
diff --git a/mojo/gles2/command_buffer_client_impl.cc b/mojo/gles2/command_buffer_client_impl.cc
index 14f0569ce1495c1f9ae994a8fdec6660abf305d6..5d778ab283992450bcf8cfc7fccca8432593cac8 100644
--- a/mojo/gles2/command_buffer_client_impl.cc
+++ b/mojo/gles2/command_buffer_client_impl.cc
@@ -16,6 +16,7 @@
 #include "components/mus/gles2/command_buffer_type_conversions.h"
 #include "components/mus/gles2/mojo_buffer_backing.h"
 #include "components/mus/gles2/mojo_gpu_memory_buffer.h"
+#include "gpu/command_buffer/client/gpu_control_client.h"
 #include "gpu/command_buffer/common/command_buffer_id.h"
 #include "gpu/command_buffer/common/gpu_memory_buffer_support.h"
 #include "gpu/command_buffer/common/sync_token.h"
@@ -61,15 +62,11 @@ void InitializeCallback(mus::mojom::CommandBufferInitializeResultPtr* output,
 
 }  // namespace
 
-CommandBufferDelegate::~CommandBufferDelegate() {}
-
-void CommandBufferDelegate::ContextLost() {}
-
 CommandBufferClientImpl::CommandBufferClientImpl(
-    CommandBufferDelegate* delegate,
     const std::vector<int32_t>& attribs,
     mojo::ScopedMessagePipeHandle command_buffer_handle)
-    : delegate_(delegate),
+    : gpu_control_client_(nullptr),
+      destroyed_(false),
       attribs_(attribs),
       client_binding_(this),
       command_buffer_id_(),
@@ -203,6 +200,10 @@ void CommandBufferClientImpl::DestroyTransferBuffer(int32_t id) {
   command_buffer_->DestroyTransferBuffer(id);
 }
 
+void CommandBufferClientImpl::SetGpuControlClient(gpu::GpuControlClient* c) {
+  gpu_control_client_ = c;
+}
+
 gpu::Capabilities CommandBufferClientImpl::GetCapabilities() {
   return capabilities_;
 }
@@ -285,10 +286,14 @@ void CommandBufferClientImpl::SignalQuery(uint32_t query,
 }
 
 void CommandBufferClientImpl::Destroyed(int32_t lost_reason, int32_t error) {
+  if (destroyed_)
+    return;
   last_state_.context_lost_reason =
       static_cast<gpu::error::ContextLostReason>(lost_reason);
   last_state_.error = static_cast<gpu::error::Error>(error);
-  delegate_->ContextLost();
+  DCHECK(gpu_control_client_);

[piman, 2016/04/11 21:54:26]

Here too, allow it to be null?

+  gpu_control_client_->OnGpuControlLostContext();
+  destroyed_ = true;
 }
 
 void CommandBufferClientImpl::SignalAck(uint32_t id) {