Key shader on whether frag pos read is relative to top-left or bottom-left

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/14633007

git-svn-id: http://skia.googlecode.com/svn/trunk@9113 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrDrawTarget.cpp b/src/gpu/GrDrawTarget.cpp
index 7268015..aa475b3 100644
--- a/src/gpu/GrDrawTarget.cpp
+++ b/src/gpu/GrDrawTarget.cpp
@@ -407,7 +407,7 @@
 }
 
 bool GrDrawTarget::setupDstReadIfNecessary(DrawInfo* info) {
-    if (this->caps()->dstReadInShaderSupport() || !this->getDrawState().willEffectReadDst()) {
+    if (this->caps()->dstReadInShaderSupport() || !this->getDrawState().willEffectReadDstColor()) {
         return true;
     }
     GrRenderTarget* rt = this->drawState()->getRenderTarget();
@@ -639,7 +639,7 @@
         }
     }
     SkTLazy<SkRect> bounds;
-    if (this->getDrawState().willEffectReadDst()) {
+    if (this->getDrawState().willEffectReadDstColor()) {
         bounds.init();
         this->getDrawState().getViewMatrix().mapRect(bounds.get(), rect);
     }