GPU: 'Pass' SharedMemory when possible.

gpu/command_buffer/service/transfer_buffer_manager.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/transfer_buffer_manager.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 22 matching lines @@
   }
   DCHECK(!shared_memory_bytes_allocated_);
 }
 
 bool TransferBufferManager::Initialize() {
   return true;
 }
 
 bool TransferBufferManager::RegisterTransferBuffer(
     int32 id,
-    base::SharedMemory* shared_memory,
+    scoped_ptr<base::SharedMemory> shared_memory,
     size_t size) {
   if (id <= 0) {
     DVLOG(0) << "Cannot register transfer buffer with non-positive ID.";
     return false;
   }
 
   // Fail if the ID is in use.
   if (registered_buffers_.find(id) != registered_buffers_.end()) {
     DVLOG(0) << "Buffer ID already in use.";
     return false;
   }
 
-  // Duplicate the handle.
-  base::SharedMemoryHandle duped_shared_memory_handle;
-  if (!shared_memory->ShareToProcess(base::GetCurrentProcessHandle(),
-                                     &duped_shared_memory_handle)) {
-    DVLOG(0) << "Failed to duplicate shared memory handle.";
-    return false;
-  }
-  scoped_ptr<SharedMemory> duped_shared_memory(
-      new SharedMemory(duped_shared_memory_handle, false));
-
-  // Map the shared memory into this process. This validates the size.
-  if (!duped_shared_memory->Map(size)) {
-    DVLOG(0) << "Failed to map shared memory.";
-    return false;
-  }
-
-  // If it could be mapped register the shared memory with the ID.
-  scoped_refptr<Buffer> buffer =
-      make_scoped_refptr(new gpu::Buffer(duped_shared_memory.Pass(), size));
+  // Register the shared memory with the ID.
+  scoped_refptr<Buffer> buffer = new gpu::Buffer(shared_memory.Pass(), size);
 
   // Check buffer alignment is sane.
   DCHECK(!(reinterpret_cast<uintptr_t>(buffer->memory()) &
            (kCommandBufferEntrySize - 1)));
 
   shared_memory_bytes_allocated_ += size;
   TRACE_COUNTER_ID1(
       "gpu", "GpuTransferBufferMemory", this, shared_memory_bytes_allocated_);
 
   registered_buffers_[id] = buffer;
@@ skipping 22 matching lines @@
 
   BufferMap::iterator it = registered_buffers_.find(id);
   if (it == registered_buffers_.end())
     return NULL;
 
   return it->second;
 }
 
 }  // namespace gpu