Combine ViewHostMsg_{Paint,Scroll}Rect into one IPC.

The combined IPC means that scrolling only requires one transport DIB instead
of two.  Previously, we'd use one in the ScrollRect IPC to pass up the pixels
for the exposed region, and then we'd use a second one in the PaintRect IPC to
pass up the pixels for the updated scroll bar rendering.  Now all paints are
done using a single transport DIB.

Optimize RenderWidgetHostViewWin::OnPaint to only paint the damaged regions.
This means calling GetUpdateRgn and GetRegionData to enumerate the list of
damage rects.  Then only those rects are copied from the backing store.

The same optimization is not done for Linux or Mac yet.

R=brettw
BUG=29591
TEST=none

Originally reviewed at http://codereview.chromium.org/506013

Review URL: http://codereview.chromium.org/509005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35078 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 5 insertions, 5 deletions

diff --git a/chrome/browser/renderer_host/render_process_host.h b/chrome/browser/renderer_host/render_process_host.h
index aad1f83..7979d24 100644
--- a/chrome/browser/renderer_host/render_process_host.h
+++ b/chrome/browser/renderer_host/render_process_host.h
@@ -165,12 +165,12 @@ class RenderProcessHost : public IPC::Channel::Sender,
   virtual void CrossSiteClosePageACK(
       const ViewMsg_ClosePage_Params& params) = 0;
 
-  // Called on the UI thread to wait for the next PaintRect message for the
+  // Called on the UI thread to wait for the next UpdateRect message for the
   // specified render widget.  Returns true if successful, and the msg out-
-  // param will contain a copy of the received PaintRect message.
-  virtual bool WaitForPaintMsg(int render_widget_id,
-                               const base::TimeDelta& max_delay,
-                               IPC::Message* msg) = 0;
+  // param will contain a copy of the received UpdateRect message.
+  virtual bool WaitForUpdateMsg(int render_widget_id,
+                                const base::TimeDelta& max_delay,
+                                IPC::Message* msg) = 0;
 
   // Called when a received message cannot be decoded.
   virtual void ReceivedBadMessage(uint32 msg_type) = 0;