Revert "Bug fix: TranferBufferManager's SharedMemory memory usage reporting was wrong"

gpu/command_buffer/common/buffer.cc

Index: gpu/command_buffer/common/buffer.cc
diff --git a/gpu/command_buffer/common/buffer.cc b/gpu/command_buffer/common/buffer.cc
index c8d6bbc6045206095202bc2172ced5b38e2de9c9..c5f0d554559f6bafbf49b701ba3c0057ddfb53fe 100644
--- a/gpu/command_buffer/common/buffer.cc
+++ b/gpu/command_buffer/common/buffer.cc
@@ -14,10 +14,6 @@
 
 namespace gpu {
 
-bool BufferBacking::is_shared() const {
-  return false;
-}
-
 base::SharedMemoryHandle BufferBacking::shared_memory_handle() const {
   return base::SharedMemoryHandle();
 }
@@ -29,10 +25,6 @@ SharedMemoryBufferBacking::SharedMemoryBufferBacking(
 
 SharedMemoryBufferBacking::~SharedMemoryBufferBacking() {}
 
-bool SharedMemoryBufferBacking::is_shared() const {
-  return true;
-}
-
 base::SharedMemoryHandle SharedMemoryBufferBacking::shared_memory_handle()
     const {
   return shared_memory_->handle();