Gave GrClip an SkClipStack-style iterator

http://codereview.appspot.com/6434046/



git-svn-id: http://skia.googlecode.com/svn/trunk@4723 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrInOrderDrawBuffer.cpp b/src/gpu/GrInOrderDrawBuffer.cpp
index 24efb37..d0bb225 100644
--- a/src/gpu/GrInOrderDrawBuffer.cpp
+++ b/src/gpu/GrInOrderDrawBuffer.cpp
@@ -126,7 +126,11 @@
         bool disabledClip = false;
         if (drawState->isClipState() && fClip.isRect()) {
 
-            GrRect clipRect = fClip.getRect(0);
+            GrClip::Iter iter(fClip, GrClip::Iter::kBottom_IterStart);
+            const GrClip::Iter::Clip* clip = iter.next();
+            GrAssert(NULL != clip && NULL != clip->fRect);
+
+            GrRect clipRect = *clip->fRect;
             // If the clip rect touches the edge of the viewport, extended it
             // out (close) to infinity to avoid bogus intersections.
             // We might consider a more exact clip to viewport if this