Make rendering timeouts work even if paint data received early

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/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 1315 matching lines @@
 
 // Message sent from the renderer to the browser when the suggested co-ordinates
 // of the anchor for a HTML form validation message have changed.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_MoveValidationMessage,
                     gfx::Rect /* anchor rectangle in root view coordinate */)
 
 // Sent once a paint happens after the first non empty layout. In other words,
 // after the frame widget has painted something.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_DidFirstVisuallyNonEmptyPaint)
 
+// Send after a paint happens after any page commit, including a blank one.

[Charlie Reis, 2015/09/30 20:36:19]

nit: Sent

Also, we shouldn't really be adding new ViewHostMsgs at this point.  But maybe
we just need to rename all the widget ones to WidgetHostMsg.  A TODO is probably
fine.

[kenrb, 2015/09/30 21:25:02]

Done. Bug 537793 filed for that.

+IPC_MESSAGE_ROUTED0(ViewHostMsg_DidFirstPaintAfterLoad)
+
 #if defined(OS_ANDROID)
 // Response to ViewMsg_FindMatchRects.
 //
 // |version| will contain the current version number of the renderer's find
 // match list (incremented whenever they change), which should be passed in the
 // next call to ViewMsg_FindMatchRects.
 //
 // |rects| will either contain a list of the enclosing rects of all matches
 // found by the most recent Find operation, or will be empty if |version| is not
 // greater than the |current_version| passed to ViewMsg_FindMatchRects (hence
@@ skipping 39 matching lines @@
 // Instructs the browser to start plugin IME.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_StartPluginIme)
 
 // Receives content of a web page as plain text.
 IPC_MESSAGE_ROUTED1(ViewMsg_GetRenderedTextCompleted, std::string);
 #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.