Make Gr clear take a rect for a partial-clear

Review URL: http://codereview.appspot.com/4442093/



git-svn-id: http://skia.googlecode.com/svn/trunk@1203 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/GrInOrderDrawBuffer.h b/gpu/include/GrInOrderDrawBuffer.h
index 03a2f2d..b26cd72 100644
--- a/gpu/include/GrInOrderDrawBuffer.h
+++ b/gpu/include/GrInOrderDrawBuffer.h
@@ -100,7 +100,7 @@
                                int* vertexCount,
                                int* indexCount) const;
 
-    virtual void clear(GrColor color);
+    virtual void clear(const GrIRect* rect, GrColor color);
 
 private:
 
@@ -119,6 +119,7 @@
 
     struct Clear {
         int fBeforeDrawIdx;
+        GrIRect fRect;
         GrColor fColor;
     };