Turn NVPR on by default (but off in tools).

include/gpu/GrContextFactory.h

Index: include/gpu/GrContextFactory.h
diff --git a/include/gpu/GrContextFactory.h b/include/gpu/GrContextFactory.h
index 389c398c7c5720166c493503879d9e34ce687b93..333afd29f6b71b0346079346ded27307bc673f4a 100644
--- a/include/gpu/GrContextFactory.h
+++ b/include/gpu/GrContextFactory.h
@@ -26,12 +26,15 @@
  * GrContexts backed by different types of GL contexts. It manages creating the
  * GL context and a GrContext that uses it. The GL/Gr contexts persist until the
  * factory is destroyed (though the caller can always grab a ref on the returned
- * GrContext to make it outlive the factory).
+ * Gr and GL contexts to make them outlive the factory).
  */
 class GrContextFactory : public SkNoncopyable {
 public:
     /**
-     * Types of GL contexts supported.
+     * Types of GL contexts supported. For historical and testing reasons the native GrContext will
+     * not use "GL_NV_path_rendering" even when the driver supports it. There is a separate context
+     * type that does not remove NVPR support and which will fail when the driver does not support
+     * the extension.
      */
     enum GLContextType {
       kNative_GLContextType,
@@ -41,6 +44,9 @@ public:
 #if SK_MESA
       kMESA_GLContextType,
 #endif
+      /** Similar to kNative but does not filter NVPR. It will fail if the GL driver does not
+          support NVPR */
+      kNVPR_GLContextType,
       kNull_GLContextType,
       kDebug_GLContextType,
 
@@ -73,6 +79,8 @@ public:
             case kMESA_GLContextType:
                 return "mesa";
 #endif
+            case kNVPR_GLContextType:
+                return "nvpr";
             case kDebug_GLContextType:
                 return "debug";
             default:
@@ -87,6 +95,7 @@ public:
 
     void destroyContexts() {
         for (int i = 0; i < fContexts.count(); ++i) {
+            fContexts[i].fGLContext->makeCurrent();
             fContexts[i].fGrContext->unref();
             fContexts[i].fGLContext->unref();
         }
@@ -107,6 +116,7 @@ public:
         SkAutoTUnref<SkGLContextHelper> glCtx;
         SkAutoTUnref<GrContext> grCtx;
         switch (type) {
+            case kNVPR_GLContextType: // fallthru
             case kNative_GLContextType:
                 glCtx.reset(SkNEW(SkNativeGLContext));
                 break;
@@ -134,7 +144,22 @@ public:
         if (!glCtx.get()->init(kBogusSize, kBogusSize)) {
             return NULL;
         }
-        GrBackendContext p3dctx = reinterpret_cast<GrBackendContext>(glCtx.get()->gl());
+
+        // Ensure NVPR is available for the NVPR type and block it from other types.
+        SkAutoTUnref<const GrGLInterface> glInterface(SkRef(glCtx.get()->gl()));
+        if (kNVPR_GLContextType == type) {
+            if (!glInterface->hasExtension("GL_NV_path_rendering")) {
+                return NULL;
+            }
+        } else {
+            glInterface.reset(GrGLInterfaceRemoveNVPR(glInterface));
+            if (!glInterface) {
+                return NULL;
+            }
+        }
+
+        glCtx->makeCurrent();
+        GrBackendContext p3dctx = reinterpret_cast<GrBackendContext>(glInterface.get());
         grCtx.reset(GrContext::Create(kOpenGL_GrBackend, p3dctx));
         if (!grCtx.get()) {
             return NULL;