Allow WebExternalTextureLayers to receive a bitmap along with a mailbox

webkit/renderer/compositor_bindings/web_external_bitmap_impl.cc

+// 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.
+
+#include "webkit/renderer/compositor_bindings/web_external_bitmap_impl.h"
+
+#include "base/memory/shared_memory.h"
+
+namespace webkit {
+
+namespace {
+
+SharedMemoryAllocationFunction g_memory_allocator;
+
+}  // namespace
+
+void SetSharedMemoryAllocationFunction(
+    SharedMemoryAllocationFunction allocator) {
+  g_memory_allocator = allocator;
+}
+
+WebExternalBitmapImpl::WebExternalBitmapImpl() {}
+
+WebExternalBitmapImpl::~WebExternalBitmapImpl() {}
+
+void WebExternalBitmapImpl::setSize(WebKit::WebSize size) {
+  if (size != size_) {
+    shared_memory_ = g_memory_allocator(size.width * size.height * 4);
+    size_ = size;
+  }
+}
+
+WebKit::WebSize WebExternalBitmapImpl::size() {
+  return size_;
+}
+
+uint8* WebExternalBitmapImpl::pixels() {
+  return static_cast<uint8*>(shared_memory_->memory());
+}
+
+}  // namespace webkit