Revert of Removing the ChildProcessHostMsg_SyncAllocateSharedMemory IPC message.

content/common/child_process_messages.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.
 
 // Common IPC messages used for child processes.
 // Multiply-included message file, hence no include guard.
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 158 matching lines @@
 // OS. Please see ChildProcessHost::PreCacheFont for details.
 IPC_SYNC_MESSAGE_CONTROL1_0(ChildProcessHostMsg_PreCacheFont,
                             LOGFONT /* font data */)
 
 // Release the cached font
 IPC_MESSAGE_CONTROL0(ChildProcessHostMsg_ReleaseCachedFonts)
 #endif  // defined(OS_WIN)
 
 // Asks the browser to create a block of shared memory for the child process to
 // fill in and pass back to the browser.
+IPC_SYNC_MESSAGE_CONTROL1_1(ChildProcessHostMsg_SyncAllocateSharedMemory,
+                            uint32_t /* buffer size */,
+                            base::SharedMemoryHandle)
+
+// Asks the browser to create a block of shared memory for the child process to
+// fill in and pass back to the browser.
 IPC_SYNC_MESSAGE_CONTROL2_1(ChildProcessHostMsg_SyncAllocateSharedBitmap,
                             uint32_t /* buffer size */,
                             cc::SharedBitmapId,
                             base::SharedMemoryHandle)
 
 // Informs the browser that the child allocated a shared bitmap.
 IPC_MESSAGE_CONTROL3(ChildProcessHostMsg_AllocatedSharedBitmap,
                      uint32_t /* buffer size */,
                      base::SharedMemoryHandle,
                      cc::SharedBitmapId)
@@ skipping 28 matching lines @@
 // memory.
 IPC_MESSAGE_CONTROL1(ChildProcessHostMsg_DeletedDiscardableSharedMemory,
                      discardable_memory::DiscardableSharedMemoryId)
 
 #if defined(OS_LINUX)
 // Asks the browser to change the priority of thread.
 IPC_MESSAGE_CONTROL2(ChildProcessHostMsg_SetThreadPriority,
                      base::PlatformThreadId,
                      base::ThreadPriority)
 #endif