Wrap NV_path_rendering API with GrGLPathRendering

src/gpu/gl/GrGLCaps.cpp

Index: src/gpu/gl/GrGLCaps.cpp
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index f3329578ce76af14cce0be0afca5f93346799c2f..ce2583f5ac5f1f114e7eccb21454278f05469434 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -312,24 +312,39 @@ bool GrGLCaps::init(const GrGLContextInfo& ctxInfo, const GrGLInterface* gli) {
     fMaxRenderTargetSize = SkTMin(fMaxTextureSize, fMaxRenderTargetSize);
 
     fPathRenderingSupport = ctxInfo.hasExtension("GL_NV_path_rendering");
+    fPathRenderingV13Support = false;
 
     if (fPathRenderingSupport) {
         if (kGL_GrGLStandard == standard) {
+            fPathRenderingSupport = ctxInfo.hasExtension("GL_EXT_direct_state_access");
+
+            // NVPR v1.3 introduces additional methods to the desktop API. We know the particular
+            // context we are on has v1.3 support as long as all the new methods are non-null
+            // their supporting GL functionality is present.
+            fPathRenderingV13Support = fPathRenderingSupport &&
+                                       NULL != gli->fFunctions.fStencilThenCoverFillPath &&
+                                       NULL != gli->fFunctions.fStencilThenCoverStrokePath &&
+                                       NULL != gli->fFunctions.fStencilThenCoverFillPathInstanced &&
+                                       NULL != gli->fFunctions.fStencilThenCoverStrokePathInstanced &&
+                                       (NULL != gli->fFunctions.fProgramPathFragmentInputGen &&
+                                         (ctxInfo.version() >= GR_GL_VER(4,3) ||
+                                          ctxInfo.hasExtension("GL_ARB_program_interface_query")));
+
             // We need one of the two possible texturing methods: using fixed function pipeline
-            // (PathTexGen, texcoords, ...)  or using the newer NVPR API additions that support
-            // setting individual fragment inputs with ProgramPathFragmentInputGen. The API
-            // additions are detected by checking the existence of the function. Eventually we may
-            // choose to remove the fixed function codepath.
+            // (PathTexGen, texcoords, ...)  or using the newer NVPR v1.3 API additions that support
+            // setting individual fragment inputs with ProgramPathFragmentInputGen. Eventually we
+            // may choose to remove the fixed function codepath.
             // Set fMaxFixedFunctionTextureCoords = 0 here if you want to force
             // ProgramPathFragmentInputGen usage on desktop.
-            fPathRenderingSupport = ctxInfo.hasExtension("GL_EXT_direct_state_access") &&
-                (fMaxFixedFunctionTextureCoords > 0 ||
-                 ((ctxInfo.version() >= GR_GL_VER(4,3) ||
-                   ctxInfo.hasExtension("GL_ARB_program_interface_query")) &&
-                  NULL != gli->fFunctions.fProgramPathFragmentInputGen));
+            if (0 == fMaxFixedFunctionTextureCoords && !fPathRenderingV13Support) {
+                fPathRenderingSupport = false;
+            }
         } else {
             // Note: path rendering is not yet implemented for GLES.
             fPathRenderingSupport = ctxInfo.version() >= GR_GL_VER(3,1) && false;
+
+            // NVpr v1.3 support is always present on GLES.
+            fPathRenderingV13Support = fPathRenderingSupport;
         }
     }