Make the Sk GL context class an abstract base class

tests/GLInterfaceValidationTest.cpp

Index: tests/GLInterfaceValidationTest.cpp
diff --git a/tests/GLInterfaceValidationTest.cpp b/tests/GLInterfaceValidationTest.cpp
index 797ba72cc07faf93b61b1ac8c30990f1a2a053ca..83f9e2eae2f99622a15ba5ba6429c80c78b4deeb 100755
--- a/tests/GLInterfaceValidationTest.cpp
+++ b/tests/GLInterfaceValidationTest.cpp
@@ -17,20 +17,20 @@ DEF_GPUTEST(GLInterfaceValidation, reporter, factory) {
         GrContextFactory::GLContextType glCtxType = (GrContextFactory::GLContextType)i;
         // this forces the factory to make the context if it hasn't yet
         factory->get(glCtxType);
-        SkGLContextHelper* glCtxHelper = factory->getGLContext(glCtxType);
+        SkGLContext* glCtx = factory->getGLContext(glCtxType);
 
         // We're supposed to fail the NVPR context type when we the native context that does not
         // support the NVPR extension.
         if (GrContextFactory::kNVPR_GLContextType == glCtxType &&
             factory->getGLContext(GrContextFactory::kNative_GLContextType) &&
             !factory->getGLContext(GrContextFactory::kNative_GLContextType)->hasExtension("GL_NV_path_rendering")) {
-            REPORTER_ASSERT(reporter, NULL == glCtxHelper);
+            REPORTER_ASSERT(reporter, NULL == glCtx);
             continue;
         }
 
-        REPORTER_ASSERT(reporter, glCtxHelper);
-        if (glCtxHelper) {
-            const GrGLInterface* interface = glCtxHelper->gl();
+        REPORTER_ASSERT(reporter, glCtx);
+        if (glCtx) {
+            const GrGLInterface* interface = glCtx->gl();
             REPORTER_ASSERT(reporter, interface->validate());
         }
     }