Renderer process can allocate anonymous shared memory without help from browser process on Windows.

content/public/test/mock_render_thread.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 "content/public/test/mock_render_thread.h"
 
 #include "base/process_util.h"
 #include "base/message_loop_proxy.h"
 #include "content/common/view_messages.h"
 #include "ipc/ipc_message_utils.h"
@@ skipping 123 matching lines @@
 
 void MockRenderThread::WidgetRestored() {
 }
 
 void MockRenderThread::EnsureWebKitInitialized() {
 }
 
 void MockRenderThread::RecordUserMetrics(const std::string& action) {
 }
 
-base::SharedMemoryHandle MockRenderThread::HostAllocateSharedMemoryBuffer(
-    uint32 buffer_size) {
-  base::SharedMemory shared_buf;
-  if (!shared_buf.CreateAndMapAnonymous(buffer_size)) {
+scoped_ptr<base::SharedMemory>
+    MockRenderThread::HostAllocateSharedMemoryBuffer(
+        uint32 buffer_size) {
+  scoped_ptr<base::SharedMemory> shared_buf(new base::SharedMemory);
+  if (!shared_buf->CreateAndMapAnonymous(buffer_size)) {
     NOTREACHED() << "Cannot map shared memory buffer";
-    return base::SharedMemory::NULLHandle();
+    return scoped_ptr<base::SharedMemory>();
   }
-  base::SharedMemoryHandle handle;
-  shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), &handle);
-  return handle;
+
+  return scoped_ptr<base::SharedMemory>(shared_buf.release());
 }
 
 void MockRenderThread::RegisterExtension(v8::Extension* extension) {
 }
 
 void MockRenderThread::ScheduleIdleHandler(int64 initial_delay_ms) {
 }
 
 void MockRenderThread::IdleHandler() {
 }
@@ skipping 65 matching lines @@
 void MockRenderThread::OnDuplicateSection(
     base::SharedMemoryHandle renderer_handle,
     base::SharedMemoryHandle* browser_handle) {
   // We don't have to duplicate the input handles since RenderViewTest does not
   // separate a browser process from a renderer process.
   *browser_handle = renderer_handle;
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace content