Populate NVPR functions when run with command buffer

Populate the NV_path_rendering functions provided by
CHROMIUM_path_rendering when the tools are being run with
command buffer API.

BUG=skia:2992

Review URL: https://codereview.chromium.org/1510163003
diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index da3c656..9cdc9f4 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -39,6 +39,9 @@
     GrGLInterface* newInterface = GrGLInterface::NewClone(interface);
 
     newInterface->fExtensions.remove("GL_NV_path_rendering");
+    newInterface->fExtensions.remove("GL_CHROMIUM_path_rendering");
+    newInterface->fFunctions.fMatrixLoadf = nullptr;
+    newInterface->fFunctions.fMatrixLoadIdentity = nullptr;
     newInterface->fFunctions.fPathCommands = nullptr;
     newInterface->fFunctions.fPathParameteri = nullptr;
     newInterface->fFunctions.fPathParameterf = nullptr;