Add isSingleComponent bool to getConstantColorComponent

src/gpu/GrProcessor.cpp

Index: src/gpu/GrProcessor.cpp
diff --git a/src/gpu/GrProcessor.cpp b/src/gpu/GrProcessor.cpp
index 45298b522d3ef9e1bf367c19ea8989a8b02f900e..79542c83b5f5d9898785e1d869491ff71b4e3d15 100644
--- a/src/gpu/GrProcessor.cpp
+++ b/src/gpu/GrProcessor.cpp
@@ -88,4 +88,20 @@ void GrProcessor::assertEquality(const GrProcessor& other) const {
         SkASSERT(this->textureAccess(i) == other.textureAccess(i));
     }
 }
+
+void GrProcessor::InvarientOutput::validate() const {
+    if (isSingleComponent) {
+        SkASSERT(0 == validFlags || kRGBA_GrColorComponentFlags == validFlags);
+        if (kRGBA_GrColorComponentFlags == validFlags) {
+            SkASSERT(this->colorComponentsAllEqual());
+        }
+    }

[bsalomon, 2014/09/30 00:41:01]

else {
  SkASSERT(!kRGBA || !<all components the same>);
}
?

[egdaniel, 2014/10/02 14:58:33]

Once we have better helper functions that will set the correct single/four
component bool, I will add this assert in

+}
+
+bool GrProcessor::InvarientOutput::colorComponentsAllEqual() const {
+    unsigned colorA = GrColorUnpackA(color);
+    return(GrColorUnpackR(color) == colorA &&
+           GrColorUnpackG(color) == colorA &&
+           GrColorUnpackB(color) == colorA);
+}
 #endif