Add support for passing an arbitrary parameter to an IPC message handler. The motivation is for Web…

chrome/renderer/pepper/pepper_flash_drm_renderer_host.cc

Index: chrome/renderer/pepper/pepper_flash_drm_renderer_host.cc
===================================================================
--- chrome/renderer/pepper/pepper_flash_drm_renderer_host.cc	(revision 270145)
+++ chrome/renderer/pepper/pepper_flash_drm_renderer_host.cc	(working copy)
@@ -32,10 +32,10 @@
 int32_t PepperFlashDRMRendererHost::OnResourceMessageReceived(
     const IPC::Message& msg,
     ppapi::host::HostMessageContext* context) {
-  IPC_BEGIN_MESSAGE_MAP(PepperFlashDRMRendererHost, msg)
-  PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_FlashDRM_GetVoucherFile,
-                                      OnGetVoucherFile)
-  IPC_END_MESSAGE_MAP()
+  PPAPI_BEGIN_MESSAGE_MAP(PepperFlashDRMRendererHost, msg)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(PpapiHostMsg_FlashDRM_GetVoucherFile,
+                                        OnGetVoucherFile)
+  PPAPI_END_MESSAGE_MAP()
   return PP_ERROR_FAILED;
 }