Use an explicitly-sized int type across the IPC boundary.

content/common/view_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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "base/string16.h"
@@ skipping 2285 matching lines @@
 #if defined(OS_POSIX)
 // On POSIX, we cannot allocated shared memory from within the sandbox, so
 // this call exists for the renderer to ask the browser to allocate memory
 // on its behalf. We return a file descriptor to the POSIX shared memory.
 // If the |cache_in_browser| flag is |true|, then a copy of the shmem is kept
 // by the browser, and it is the caller's repsonsibility to send a
 // ViewHostMsg_FreeTransportDIB message in order to release the cached shmem.
 // In all cases, the caller is responsible for deleting the resulting
 // TransportDIB.
 IPC_SYNC_MESSAGE_CONTROL2_1(ViewHostMsg_AllocTransportDIB,
-                            size_t, /* bytes requested */
+                            uint32_t, /* bytes requested */
                             bool, /* cache in the browser */
                             TransportDIB::Handle /* DIB */)
 
 // Since the browser keeps handles to the allocated transport DIBs, this
 // message is sent to tell the browser that it may release them when the
 // renderer is finished with them.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_FreeTransportDIB,
                      TransportDIB::Id /* DIB id */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.