Make drawRect preserve vertex attrib state and push/pop the geom sources.

Also, add some balancing calls for setIndexSource*()
Review URL: https://codereview.chromium.org/13468004

git-svn-id: http://skia.googlecode.com/svn/trunk@8499 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrAARectRenderer.cpp b/src/gpu/GrAARectRenderer.cpp
index 0093b08..6f074e6 100644
--- a/src/gpu/GrAARectRenderer.cpp
+++ b/src/gpu/GrAARectRenderer.cpp
@@ -178,6 +178,7 @@
     target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1,
                                  kVertsPerAAFillRect,
                                  kIndicesPerAAFillRect);
+    target->resetIndexSource();
 }
 
 void GrAARectRenderer::strokeAARect(GrGpu* gpu,