Remove page IDs from three WebContentsObserver APIs that don't need it.

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index e713f05bae2b46cef639aaa8f29444c7cfce3d2f..0f11d50445143496d45012ec4b752f921fec1110 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1161,8 +1161,7 @@ IPC_MESSAGE_ROUTED0(ViewHostMsg_DocumentAvailableInMainFrame)
 
 // Sent when after the onload handler has been invoked for the document
 // in the top-level frame.
-IPC_MESSAGE_ROUTED1(ViewHostMsg_DocumentOnLoadCompletedInMainFrame,
-                    int32 /* page_id */)
+IPC_MESSAGE_ROUTED0(ViewHostMsg_DocumentOnLoadCompletedInMainFrame)
 
 // Sent when the renderer loads a resource from its memory cache.
 // The security info is non empty if the resource was originally loaded over
@@ -1648,14 +1647,12 @@ IPC_MESSAGE_CONTROL3(ViewHostMsg_DidLose3DContext,
 IPC_MESSAGE_ROUTED0(ViewHostMsg_WillInsertBody)
 
 // Notification that the urls for the favicon of a site has been determined.
-IPC_MESSAGE_ROUTED2(ViewHostMsg_UpdateFaviconURL,
-                    int32 /* page_id */,
+IPC_MESSAGE_ROUTED1(ViewHostMsg_UpdateFaviconURL,
                     std::vector<content::FaviconURL> /* candidates */)
 
 // Sent once a paint happens after the first non empty layout. In other words
 // after the page has painted something.
-IPC_MESSAGE_ROUTED1(ViewHostMsg_DidFirstVisuallyNonEmptyPaint,
-                    int /* page_id */)
+IPC_MESSAGE_ROUTED0(ViewHostMsg_DidFirstVisuallyNonEmptyPaint)
 
 // Sent by the renderer to the browser to start a vibration with the given
 // duration.