One signature for creating unit tests that run on premade GrContexts

tests/GpuColorFilterTest.cpp

Index: tests/GpuColorFilterTest.cpp
diff --git a/tests/GpuColorFilterTest.cpp b/tests/GpuColorFilterTest.cpp
index 186f8c699f401f8cf769d19b2b313ce60497da0e..1788770e5b5510eb62a6d075a6876a784fc9e153 100644
--- a/tests/GpuColorFilterTest.cpp
+++ b/tests/GpuColorFilterTest.cpp
@@ -32,7 +32,7 @@ static GrColor filterColor(const GrColor& color, uint32_t flags)  {
     return color & mask;
 }
 
-DEF_GPUTEST_FOR_ALL_CONTEXTS(GpuColorFilter, reporter, context) {
+DEF_GPUTEST_FOR_ALL_CONTEXTS(GpuColorFilter, reporter, ctxInfo) {
     struct GetConstantComponentTestCase {
         // "Shape drawn with"
         uint32_t inputComponents; // "rgb of", "red of", "alpha of", ...
@@ -99,7 +99,7 @@ DEF_GPUTEST_FOR_ALL_CONTEXTS(GpuColorFilter, reporter, context) {
     for (size_t i = 0; i < SK_ARRAY_COUNT(filterTests); ++i) {
         const GetConstantComponentTestCase& test = filterTests[i];
         auto cf(SkColorFilter::MakeModeFilter(test.filterColor, test.filterMode));
-        SkAutoTUnref<const GrFragmentProcessor> fp( cf->asFragmentProcessor(context));
+        SkAutoTUnref<const GrFragmentProcessor> fp( cf->asFragmentProcessor(ctxInfo.fGrContext));
         REPORTER_ASSERT(reporter, fp);
         GrInvariantOutput inout(test.inputColor,
                                 static_cast<GrColorComponentFlags>(test.inputComponents),