Revert of Removing the ChildProcessHostMsg_SyncAllocateSharedMemory IPC message.

content/common/child_process_host_impl.h

 // 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.
 
 #ifndef CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_
 #define CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 23 matching lines @@
 class ChildProcessHostDelegate;
 
 // Provides common functionality for hosting a child process and processing IPC
 // messages between the host and the child process. Users are responsible
 // for the actual launching and terminating of the child processes.
 class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
                                             public IPC::Listener {
  public:
   ~ChildProcessHostImpl() override;
 
+  // Public and static for reuse by RenderMessageFilter.
+  static void AllocateSharedMemory(
+      size_t buffer_size, base::ProcessHandle child_process,
+      base::SharedMemoryHandle* handle);
+
   // Returns a unique ID to identify a child process. On construction, this
   // function will be used to generate the id_, but it is also used to generate
   // IDs for the RenderProcessHost, which doesn't inherit from us, and whose IDs
   // must be unique for all child processes.
   //
   // This function is threadsafe since RenderProcessHost is on the UI thread,
   // but normally this will be used on the IO thread.
   //
   // This will never return ChildProcessHost::kInvalidUniqueID.
   static int GenerateChildProcessUniqueId();
@@ skipping 27 matching lines @@
   explicit ChildProcessHostImpl(ChildProcessHostDelegate* delegate);
 
   // IPC::Listener methods:
   bool OnMessageReceived(const IPC::Message& msg) override;
   void OnChannelConnected(int32_t peer_pid) override;
   void OnChannelError() override;
   void OnBadMessageReceived(const IPC::Message& message) override;
 
   // Message handlers:
   void OnShutdownRequest();
+  void OnAllocateSharedMemory(uint32_t buffer_size,
+                              base::SharedMemoryHandle* handle);
   void OnAllocateGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
                                  uint32_t width,
                                  uint32_t height,
                                  gfx::BufferFormat format,
                                  gfx::BufferUsage usage,
                                  gfx::GpuMemoryBufferHandle* handle);
   void OnDeletedGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
                                 const gpu::SyncToken& sync_token);
 
   // Initializes the IPC channel and returns true on success. |channel_| must be
@@ skipping 10 matching lines @@
   // thread, we don't have a IPC::ChannelProxy and so we manage filters
   // manually.
   std::vector<scoped_refptr<IPC::MessageFilter> > filters_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildProcessHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_