Make shared memory allocation possible for all child process types.

content/common/child_thread.h

Index: content/common/child_thread.h
===================================================================
--- content/common/child_thread.h	(revision 105562)
+++ content/common/child_thread.h	(working copy)
@@ -8,6 +8,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/shared_memory.h"
 #include "content/common/content_export.h"
 #include "content/common/message_router.h"
 #include "webkit/glue/resource_loader_bridge.h"
@@ -50,6 +51,12 @@
   virtual webkit_glue::ResourceLoaderBridge* CreateBridge(
       const webkit_glue::ResourceLoaderBridge::RequestInfo& request_info);
 
+  // Allocates a block of shared memory of the given size and
+  // maps in into the address space. Returns NULL of failure.
+  // Note: On posix, this requires a sync IPC to the browser process,
+  // but on windows the child process directly allocates the block.
+  base::SharedMemory* AllocateSharedMemory(size_t buf_size);
+
   ResourceDispatcher* resource_dispatcher();
 
   SocketStreamDispatcher* socket_stream_dispatcher() {