Add multi-process GpuMemoryBuffer framework.

This adds a multi-process framework for reading/writing directly to
memory that the 3D graphics hardware can use for rendering without
any costly copying having to be done on the GPU process side.

A GpuMemoryBuffer is a type of shared memory that can be accessed
by the GPU. The high level procedure required to allocate this type
of memory is almost exactly the same as that for standard shared
memory. Only the browser process can allocated the memory and it
needs to be shared and registered with the GPU process before it can
be used.

This also adds a GpuMemoryBuffer type that is backed by standard
shared memory for testing purposes.

TEST=gpu_unittests --gtest_filter=MockGpuMemoryBufferTest.Lifecycle
BUG=261649

Review URL: https://codereview.chromium.org/19762004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230248 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 45 insertions, 0 deletions

diff --git a/content/common/gpu/client/gpu_memory_buffer_impl.h b/content/common/gpu/client/gpu_memory_buffer_impl.h
new file mode 100644
index 0000000..3858c3f
--- /dev/null
+++ b/content/common/gpu/client/gpu_memory_buffer_impl.h
@@ -0,0 +1,45 @@
+// Copyright 2013 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.
+
+#ifndef CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_H_
+#define CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "ui/gfx/gpu_memory_buffer.h"
+#include "ui/gfx/size.h"
+
+namespace content {
+
+// Provides common implementation of a GPU memory buffer based
+// on a shared memory handle.
+class GpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
+ public:
+  GpuMemoryBufferImpl(scoped_ptr<base::SharedMemory> shared_memory,
+                      size_t width,
+                      size_t height,
+                      unsigned internalformat);
+  virtual ~GpuMemoryBufferImpl();
+
+  // Overridden from gfx::GpuMemoryBuffer:
+  virtual void Map(AccessMode mode, void** vaddr) OVERRIDE;
+  virtual void Unmap() OVERRIDE;
+  virtual bool IsMapped() const OVERRIDE;
+  virtual uint32 GetStride() const OVERRIDE;
+  virtual gfx::GpuMemoryBufferHandle GetHandle() const OVERRIDE;
+
+  static bool IsFormatValid(unsigned internalformat);
+  static size_t BytesPerPixel(unsigned internalformat);
+
+ private:
+  scoped_ptr<base::SharedMemory> shared_memory_;
+  const gfx::Size size_;
+  unsigned internalformat_;
+  bool mapped_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_H_