Test that GrFragmentProcessors work without input colors.

include/gpu/GrProcessorUnitTest.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrProcessorUnitTest_DEFINED
 #define GrProcessorUnitTest_DEFINED
 
@@ skipping 50 matching lines @@
 class GrProcessorTestFactory : SkNoncopyable {
 public:
 
     typedef const Processor* (*CreateProc)(GrProcessorTestData*);
 
     GrProcessorTestFactory(CreateProc createProc) {
         fCreateProc = createProc;
         GetFactories()->push_back(this);
     }
 
-    static const Processor* CreateStage(GrProcessorTestData* data) {
+    /** Pick a random factory function and create a processor.  */
+    static const Processor* Create(GrProcessorTestData* data) {
         VerifyFactoryCount();
         SkASSERT(GetFactories()->count());
         uint32_t idx = data->fRandom->nextRangeU(0, GetFactories()->count() - 1);
+        return CreateIdx(idx, data);
+    }
+
+    /** Number of registered factory functions */
+    static int Count() { return GetFactories()->count(); }
+
+    /** Use factory function at Index idx to create a processor. */
+    static const Processor* CreateIdx(int idx, GrProcessorTestData* data) {
         GrProcessorTestFactory<Processor>* factory = (*GetFactories())[idx];
         return factory->fCreateProc(data);
     }
 
     /*
      * A test function which verifies the count of factories.
      */
     static void VerifyFactoryCount();
 
 private:
@@ skipping 46 matching lines @@
 #define GR_DEFINE_XP_FACTORY_TEST(X)
 
 // The unit test relies on static initializers. Just declare the TestCreate function so that
 // its definitions will compile.
 #define GR_DECLARE_GEOMETRY_PROCESSOR_TEST                                                         \
     static const GrGeometryProcessor* TestCreate(GrProcessorTestData*)
 #define GR_DEFINE_GEOMETRY_PROCESSOR_TEST(X)
 
 #endif // !SK_ALLOW_STATIC_GLOBAL_INITIALIZERS
 #endif