Added preliminary support for tile rasterization with Ganesh

cc/resources/raster_mode.h

Index: cc/resources/raster_mode.h
diff --git a/cc/resources/raster_mode.h b/cc/resources/raster_mode.h
index 9868059e0b7015c5a885ed92adc117d3e08fb176..edde8cfa95c35334e55e7bcfa4f09a27ed9f5b60 100644
--- a/cc/resources/raster_mode.h
+++ b/cc/resources/raster_mode.h
@@ -21,7 +21,8 @@ enum RasterMode {
   HIGH_QUALITY_NO_LCD_RASTER_MODE = 0,
   HIGH_QUALITY_RASTER_MODE = 1,
   LOW_QUALITY_RASTER_MODE = 2,
-  NUM_RASTER_MODES = 3
+  GANESH_RASTER_MODE = 3,

[reveman, 2013/11/24 21:56:57]

I'm not sure this should be a raster mode. Raster modes exist to allow tiles to
transition from one type of raster to another. ie. low to high quality. It
doesn't seem like we would ever want a tile to transition for sw to ganesh
raster. Also, using raster mode prevents us from supporting low quality ganesh
raster.

[vmpstr, 2013/11/25 18:11:48]

I think this could be one of the ManageTileState::TileVersion::Mode enums (ie,
resource_mode, solid_color_mode, picture_pile_mode, ganesh_resource_mode?). 

+  NUM_RASTER_MODES = 4
 };
 
 scoped_ptr<base::Value> RasterModeAsValue(RasterMode mode);