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

content/browser/renderer_host/render_widget_helper.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_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 144 matching lines @@
                        int* route_id,
                        int* surface_id);
   void CreateNewFullscreenWidget(int opener_id, int* route_id, int* surface_id);
 
 #if defined(OS_POSIX)
   // Called on the IO thread to handle the allocation of a TransportDIB.  If
   // |cache_in_browser| is |true|, then a copy of the shmem is kept by the
   // browser, and it is the caller's repsonsibility to call
   // FreeTransportDIB().  In all cases, the caller is responsible for deleting
   // the resulting TransportDIB.
-  void AllocTransportDIB(size_t size,
+  void AllocTransportDIB(uint32 size,
                          bool cache_in_browser,
                          TransportDIB::Handle* result);
 
   // Called on the IO thread to handle the freeing of a transport DIB
   void FreeTransportDIB(TransportDIB::Id dib_id);
 #endif
 
  private:
   // A class used to proxy a paint message.  PaintMsgProxy objects are created
   // on the IO thread and destroyed on the UI thread.
@@ skipping 63 matching lines @@
   base::AtomicSequenceNumber next_routing_id_;
 
   ResourceDispatcherHostImpl* resource_dispatcher_host_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHelper);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_