5 files changed, 16 insertions, 8 deletions
diff --git a/src/gpu/GrOptDrawState.cpp b/src/gpu/GrOptDrawState.cpp
index 7c8710f7d6..40e0c6ce1f 100644
--- a/src/gpu/GrOptDrawState.cpp
+++ b/src/gpu/GrOptDrawState.cpp
@@ -244,16 +244,19 @@ void GrOptDrawState::computeEffectiveColorStages(const GrDrawState& ds, int* fir
 
     for (int i = 0; i < ds.numColorStages(); ++i) {
         const GrFragmentProcessor* fp = ds.getColorStage(i).getProcessor();
-        if (!fp->willUseInputColor()) {
+        fp->computeInvariantOutput(&inout);
+        if (!inout.fWillUseInputColor) {
             *firstColorStageIdx = i;
             fInputColorIsUsed = false;
         }
-        fp->computeInvariantOutput(&inout);
         if (kRGBA_GrColorComponentFlags == inout.fValidFlags) {
             *firstColorStageIdx = i + 1;
             fColor = inout.fColor;
             fInputColorIsUsed = true;
             *fixedFunctionVAToRemove |= 0x1 << kColor_GrVertexAttribBinding;
+            // Since we are clearing all previous color stages we are in a state where we have found
+            // zero stages that don't multiply the inputColor.
+            inout.fNonMulStageFound = false;
         }
     }
 }
@@ -267,9 +270,11 @@ void GrOptDrawState::computeEffectiveCoverageStages(const GrDrawState& ds,
     // Don't do any optimizations on coverage stages. It should not be the case where we do not use
     // input coverage in an effect
 #ifdef OptCoverageStages
+    GrProcessor::InvariantOutput inout;
     for (int i = 0; i < ds.numCoverageStages(); ++i) {
-        const GrProcessor* processor = ds.getCoverageStage(i).getProcessor();
-        if (!processor->willUseInputColor()) {
+        const GrFragmentProcessor* fp = ds.getCoverageStage(i).getProcessor();
+        fp->computeInvariantOutput(&inout);
+        if (!inout.fWillUseInputColor) {
             *firstCoverageStageIdx = i;
             fInputCoverageIsUsed = false;
         }
diff --git a/src/gpu/GrProcessor.cpp b/src/gpu/GrProcessor.cpp
index bf65cb0fb9..04401c8adf 100644
--- a/src/gpu/GrProcessor.cpp
+++ b/src/gpu/GrProcessor.cpp
@@ -133,6 +133,9 @@ void GrProcessor::InvariantOutput::validate() const {
     }
 
     SkASSERT(this->validPreMulColor());
+
+    // If we claim that we are not using the input color we must not be modulating the input.
+    SkASSERT(fNonMulStageFound || fWillUseInputColor);
 }
 
 bool GrProcessor::InvariantOutput::colorComponentsAllEqual() const {
diff --git a/src/gpu/effects/GrConvexPolyEffect.cpp b/src/gpu/effects/GrConvexPolyEffect.cpp
index bafa64d13a..c84b540850 100644
--- a/src/gpu/effects/GrConvexPolyEffect.cpp
+++ b/src/gpu/effects/GrConvexPolyEffect.cpp
@@ -46,7 +46,7 @@ private:
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
         if (fRect.isEmpty()) {
             // An empty rect will have no coverage anywhere.
-            inout->setToTransparentBlack();
+            inout->mulByKnownAlpha(0);
         } else {
             inout->mulByUnknownAlpha();
         }
diff --git a/src/gpu/effects/GrDitherEffect.cpp b/src/gpu/effects/GrDitherEffect.cpp
index 068a23eae7..643829b848 100644
--- a/src/gpu/effects/GrDitherEffect.cpp
+++ b/src/gpu/effects/GrDitherEffect.cpp
@@ -50,7 +50,7 @@ private:
 };
 
 void DitherEffect::onComputeInvariantOutput(InvariantOutput* inout) const {
-    inout->setToUnknown();
+    inout->setToUnknown(InvariantOutput::kWill_ReadInput);
 }
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/src/gpu/effects/GrYUVtoRGBEffect.cpp b/src/gpu/effects/GrYUVtoRGBEffect.cpp
index f280d1bdd4..b18bd7fa01 100644
--- a/src/gpu/effects/GrYUVtoRGBEffect.cpp
+++ b/src/gpu/effects/GrYUVtoRGBEffect.cpp
@@ -99,7 +99,6 @@ private:
         this->addTextureAccess(&fYAccess);
         this->addTextureAccess(&fUAccess);
         this->addTextureAccess(&fVAccess);
-        this->setWillNotUseInputColor();
     }
 
     virtual bool onIsEqual(const GrFragmentProcessor& sBase) const {
@@ -112,7 +111,8 @@ private:
 
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
         // YUV is opaque
-        inout->setToOther(kA_GrColorComponentFlag, 0xFF << GrColor_SHIFT_A);
+        inout->setToOther(kA_GrColorComponentFlag, 0xFF << GrColor_SHIFT_A,
+                          InvariantOutput::kWill_ReadInput);
     }
 
     GrCoordTransform fCoordTransform;