Cleanup GpuMemoryManager and helpers.

gpu/command_buffer/service/gl_context_virtual.cc

Index: gpu/command_buffer/service/gl_context_virtual.cc
diff --git a/gpu/command_buffer/service/gl_context_virtual.cc b/gpu/command_buffer/service/gl_context_virtual.cc
index 563e6018757960ad6e890dae5114bb99e734e4c8..77341a9cb3f857d515d4973ba1913a5985cdc2c8 100644
--- a/gpu/command_buffer/service/gl_context_virtual.cc
+++ b/gpu/command_buffer/service/gl_context_virtual.cc
@@ -91,10 +91,6 @@ std::string GLContextVirtual::GetExtensions() {
   return shared_context_->GetExtensions();
 }
 
-bool GLContextVirtual::GetTotalGpuMemory(size_t* bytes) {
-  return shared_context_->GetTotalGpuMemory(bytes);
-}
-
 void GLContextVirtual::SetSafeToForceGpuSwitch() {
   // TODO(ccameron): This will not work if two contexts that disagree
   // about whether or not forced gpu switching may be done both share