Implement color filter as GrGLEffect

src/gpu/GrDrawTarget.cpp

Index: src/gpu/GrDrawTarget.cpp
diff --git a/src/gpu/GrDrawTarget.cpp b/src/gpu/GrDrawTarget.cpp
index c2256a84d8c7cf5cac2df1b09df4bd76b01e4f52..a31b2d9815ede4f24e47b0de2694e31559ee0c0e 100644
--- a/src/gpu/GrDrawTarget.cpp
+++ b/src/gpu/GrDrawTarget.cpp
@@ -388,16 +388,16 @@ bool GrDrawTarget::checkDraw(GrPrimitiveType type, int startVertex,
 
     SkASSERT(NULL != drawState.getRenderTarget());
 
-    for (int s = 0; s < drawState.numColorStages(); ++s) {
-        const GrEffectRef& effect = *drawState.getColorStage(s).getEffect();
+    for (int s = 0; s < drawState.effectiveColorStageCount(); ++s) {
+        const GrEffectRef& effect = *drawState.getEffectiveColorStage(s).getEffect();
         int numTextures = effect->numTextures();
         for (int t = 0; t < numTextures; ++t) {
             GrTexture* texture = effect->texture(t);
             SkASSERT(texture->asRenderTarget() != drawState.getRenderTarget());
         }
     }
-    for (int s = 0; s < drawState.numCoverageStages(); ++s) {
-        const GrEffectRef& effect = *drawState.getCoverageStage(s).getEffect();
+    for (int s = 0; s < drawState.effectiveCoverageStageCount(); ++s) {
+        const GrEffectRef& effect = *drawState.getEffectiveCoverageStage(s).getEffect();
         int numTextures = effect->numTextures();
         for (int t = 0; t < numTextures; ++t) {
             GrTexture* texture = effect->texture(t);