components: Add Exosphere component.

components/exo/shared_memory.cc

Index: components/exo/shared_memory.cc
diff --git a/components/exo/shared_memory.cc b/components/exo/shared_memory.cc
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index 0000000000000000000000000000000000000000..912cb8ca70307b2f1ddf470f05587273b96feec5
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+++ b/components/exo/shared_memory.cc
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+// Copyright 2015 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 "components/exo/shared_memory.h"
+
+#include "base/logging.h"
+#include "base/trace_event/trace_event.h"
+#include "components/exo/buffer.h"
+#include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
+#include "third_party/khronos/GLES2/gl2.h"
+#include "ui/aura/env.h"
+#include "ui/compositor/compositor.h"
+#include "ui/gfx/buffer_format_util.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/gpu_memory_buffer.h"
+
+namespace exo {
+namespace {
+
+bool IsSupportedFormat(gfx::BufferFormat format) {
+  return format == gfx::BufferFormat::RGBX_8888 ||
+         format == gfx::BufferFormat::RGBA_8888 ||
+         format == gfx::BufferFormat::BGRX_8888 ||
+         format == gfx::BufferFormat::BGRA_8888;
+}
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// SharedMemory, public:
+
+SharedMemory::SharedMemory(const base::SharedMemoryHandle& handle)
+    : shared_memory_(handle, true /* read-only */) {}
+
+SharedMemory::~SharedMemory() {}
+
+scoped_ptr<Buffer> SharedMemory::CreateBuffer(const gfx::Size& size,
+                                              gfx::BufferFormat format,
+                                              unsigned offset,
+                                              int stride) {
+  TRACE_EVENT2("exo", "SharedMemory::CreateBuffer", "size", size.ToString(),
+               "format", static_cast<int>(format));
+
+  if (!IsSupportedFormat(format)) {
+    DLOG(WARNING) << "Failed to create shm buffer. Unsupported format 0x"
+                  << static_cast<int>(format);
+    return nullptr;
+  }
+
+  if (!base::IsValueInRangeForNumericType<size_t>(stride) ||
+      gfx::RowSizeForBufferFormat(size.width(), format, 0) >
+          static_cast<size_t>(stride) ||
+      static_cast<size_t>(stride) & 3) {
+    DLOG(WARNING) << "Failed to create shm buffer. Unsupported stride "
+                  << stride;
+    return nullptr;
+  }
+
+  gfx::GpuMemoryBufferHandle handle;
+  handle.type = gfx::SHARED_MEMORY_BUFFER;
+  handle.handle = base::SharedMemory::DuplicateHandle(shared_memory_.handle());
+  handle.offset = offset;
+  handle.stride = stride;
+
+  scoped_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer =
+      aura::Env::GetInstance()
+          ->context_factory()
+          ->GetGpuMemoryBufferManager()
+          ->CreateGpuMemoryBufferFromHandle(handle, size, format);
+  if (!gpu_memory_buffer) {
+    LOG(ERROR) << "Failed to create GpuMemoryBuffer from handle";
+    return nullptr;
+  }
+
+  return make_scoped_ptr(new Buffer(gpu_memory_buffer.Pass(), GL_TEXTURE_2D));
+}
+
+}  // namespace exo