Make GPU coord transforms automatic

src/gpu/gl/GrGLEffect.cpp

Index: src/gpu/gl/GrGLEffect.cpp
diff --git a/src/gpu/gl/GrGLEffect.cpp b/src/gpu/gl/GrGLEffect.cpp
index 28be7afb345396188de0569646161590ee36b417..af351a47fe41f435ab5c9b57483dd5ad5ecaee6e 100644
--- a/src/gpu/gl/GrGLEffect.cpp
+++ b/src/gpu/gl/GrGLEffect.cpp
@@ -7,6 +7,7 @@
 
 #include "GrGLSL.h"
 #include "GrGLEffect.h"
+#include "GrCoordTransform.h"
 #include "GrDrawEffect.h"
 
 GrGLEffect::GrGLEffect(const GrBackendEffectFactory& factory)
@@ -34,6 +35,18 @@ GrGLEffect::EffectKey GrGLEffect::GenTextureKey(const GrDrawEffect& drawEffect,
     return key;
 }
 
+GrGLEffect::EffectKey GrGLEffect::GenTransformKey(const GrDrawEffect& drawEffect) {
+    EffectKey key = 0;
+    int numTransforms = (*drawEffect.effect())->numTransforms();
+    for (int index = 0; index < numTransforms; ++index) {
+        EffectKey value = GrGLCoordTransform::GenKey(drawEffect, index);
+        value <<= index * GrGLCoordTransform::kKeyBits;
+        SkASSERT(0 == (value & key)); // keys for each transform ought not to overlap
+        key |= value;
+    }
+    return key;
+}
+
 GrGLEffect::EffectKey GrGLEffect::GenAttribKey(const GrDrawEffect& drawEffect) {
     EffectKey key = 0;