Make the Sk GL context class an abstract base class

tools/PictureRenderer.cpp

Index: tools/PictureRenderer.cpp
diff --git a/tools/PictureRenderer.cpp b/tools/PictureRenderer.cpp
index 705849d01acd92348f60f506f554ccf24cf38435..ca449855d0ae507441d5aac3b8b785a9470ecfe3 100644
--- a/tools/PictureRenderer.cpp
+++ b/tools/PictureRenderer.cpp
@@ -228,7 +228,7 @@ void PictureRenderer::buildBBoxHierarchy() {
 
 void PictureRenderer::resetState(bool callFinish) {
 #if SK_SUPPORT_GPU
-    SkGLContextHelper* glContext = this->getGLContext();
+    SkGLContext* glContext = this->getGLContext();
     if (NULL == glContext) {
         SkASSERT(kBitmap_DeviceType == fDeviceType);
         return;
@@ -248,7 +248,7 @@ void PictureRenderer::purgeTextures() {
     pool->dumpPool();
 
 #if SK_SUPPORT_GPU
-    SkGLContextHelper* glContext = this->getGLContext();
+    SkGLContext* glContext = this->getGLContext();
     if (NULL == glContext) {
         SkASSERT(kBitmap_DeviceType == fDeviceType);
         return;