Modifications to GrPatherRenderer(Chain) interfaces to support clip mask manager.

R=robertphillips@google.com
Review URL: https://codereview.appspot.com/6904069

git-svn-id: http://skia.googlecode.com/svn/trunk@6741 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGpuGL_program.cpp b/src/gpu/gl/GrGpuGL_program.cpp
index 73f60ca..5850fc4 100644
--- a/src/gpu/gl/GrGpuGL_program.cpp
+++ b/src/gpu/gl/GrGpuGL_program.cpp
@@ -553,9 +553,11 @@
 
     if (!skipCoverage && (desc->fVertexLayout &GrDrawTarget::kEdge_VertexLayoutBit)) {
         desc->fVertexEdgeType = drawState.getVertexEdgeType();
+        desc->fDiscardIfOutsideEdge = drawState.getStencil().doesWrite();
     } else {
-        // use canonical value when not set to avoid cache misses
+        // Use canonical values when edge-aa is not enabled to avoid program cache misses.
         desc->fVertexEdgeType = GrDrawState::kHairLine_EdgeType;
+        desc->fDiscardIfOutsideEdge = false;
     }
 
     for (int s = 0; s < GrDrawState::kNumStages; ++s) {