content/gpu: Set up a mojom connection between browser and gpu.

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index b6ead8ebb72557f130f8a34a62b4588faba8c9ce..eb14c6d176519e0b4d26d85a03be7d957efdaf61 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -613,6 +613,10 @@ bool GpuProcessHost::Init() {
     return false;
   }
 
+  process_->child_channel()
+      ->GetAssociatedInterfaceSupport()
+      ->GetRemoteAssociatedInterface(&gpu_main_ptr_);
+
   if (!Send(new GpuMsg_Initialize(gpu_preferences)))
     return false;