Adds kind-of-live thumbnail generation for a potential tab switcher.

This listens to tab events and tries to keep thumbnails ready to go. See
thumbnail_generator.cc for a more detailed design.

This adds a painting observer to the RenderWidgetHost to enable this new
behavior, as well as a notification to allow the thumbnail generator to hook
its observer in. There is also a new notification that a backing store has been
disabled, which required making the backing stores know about their owning
widget hosts.

This component is currently disabled. We just need to uncomment the member in
Profile and it will start to work.

Original review: http://codereview.chromium.org/118420

Review URL: http://codereview.chromium.org/126101

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18540 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 0 deletions

diff --git a/chrome/common/transport_dib.h b/chrome/common/transport_dib.h
index 33c0649..5712827 100644..100755
--- a/chrome/common/transport_dib.h
+++ b/chrome/common/transport_dib.h
@@ -20,6 +20,9 @@
 namespace gfx {
 class Size;
 }
+namespace skia {
+class PlatformCanvas;
+}
 
 // -----------------------------------------------------------------------------
 // A TransportDIB is a block of memory that is used to transport pixels
@@ -84,6 +87,11 @@ class TransportDIB {
   // Map the referenced transport DIB. Returns NULL on failure.
   static TransportDIB* Map(Handle transport_dib);
 
+  // Returns a canvas using the memory of this TransportDIB. The returned
+  // pointer will be owned by the caller. The bitmap will be of the given size,
+  // which should fit inside this memory.
+  skia::PlatformCanvas* GetPlatformCanvas(int w, int h);
+
   // Return a pointer to the shared memory
   void* memory() const;