Implement support for KHR_blend_equation_advanced

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 97 matching lines @@
     GrProcessorTestFactory(CreateProc createProc) {
         fCreateProc = createProc;
         GetFactories()->push_back(this);
     }
 
     static Processor* CreateStage(SkRandom* random,
                                   GrContext* context,
                                   const GrDrawTargetCaps& caps,
                                   GrTexture* dummyTextures[]) {
         VerifyFactoryCount();
-        SkASSERT(GetFactories()->count());
-        uint32_t idx = random->nextRangeU(0, GetFactories()->count() - 1);
-        GrProcessorTestFactory<Processor>* factory = (*GetFactories())[idx];
-        return factory->fCreateProc(random, context, caps, dummyTextures);
+        int count = GetFactories()->count();
+        SkASSERT(count);
+        uint32_t idx = random->nextRangeU(0, count - 1);
+        Processor* p = (*GetFactories())[idx]->fCreateProc(random, context, caps, dummyTextures);
+        if (!p) {
+            // Factory at idx was not supported on this GrContext. Find one that is.
+            SkSTArray<8, GrProcessorTestFactory<Processor>*, true> localFactories(*GetFactories());
+            do {
+                count--;
+                SkASSERT(count);
+                SkTSwap(localFactories[idx], localFactories[count]);
+                idx = random->nextRangeU(0, count - 1);
+            } while (!(p = localFactories[idx]->fCreateProc(random, context, caps, dummyTextures)));
+        }
+        return p;
     }
 
     /*
      * A test function which verifies the count of factories.
      */
     static void VerifyFactoryCount();
 
 private:
     CreateProc fCreateProc;
 
@@ skipping 69 matching lines @@
 // its definitions will compile.
 #define GR_DECLARE_GEOMETRY_PROCESSOR_TEST                                                         \
     static GrGeometryProcessor* TestCreate(SkRandom*,                                              \
                                            GrContext*,                                             \
                                            const GrDrawTargetCaps&,                                \
                                            GrTexture* dummyTextures[2])
 #define GR_DEFINE_GEOMETRY_PROCESSOR_TEST(X)
 
 #endif // !SK_ALLOW_STATIC_GLOBAL_INITIALIZERS
 #endif