Add GrEllipseEdgeEffect.

Adds the effect that replaces the old oval rendering code. Also hooks in code to set attribute names and indices for effects.

Author: jvanverth@google.com

Review URL: https://chromiumcodereview.appspot.com/12462008

git-svn-id: http://skia.googlecode.com/svn/trunk@8092 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrTextContext.cpp b/src/gpu/GrTextContext.cpp
index db5abb4..a8defcb 100644
--- a/src/gpu/GrTextContext.cpp
+++ b/src/gpu/GrTextContext.cpp
@@ -19,6 +19,9 @@
 #include "SkStrokeRec.h"
 
 enum {
+    // glyph rendering shares this stage with edge rendering 
+    // (kEdgeEffectStage in GrContext) && SW path rendering 
+    // (kPathMaskStage in GrSWMaskHelper)
     kGlyphMaskStage = GrPaint::kTotalStages,
 };