More cleanup around GrContext, textures, and SkGr.cpp

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index e47ad15519f34a15b753062ebc9b25a1a6ea4529..d8d061a19efc87f8e52e3639462790eaec68c242 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -274,9 +274,14 @@ public:
                                  bool internalFlag = false);
 
     /**
-     * Returns true if index8 textures are supported.
+     * Can the provided configuration act as a texture?
      */
-    bool supportsIndex8PixelConfig() const;
+    bool isConfigTexturable(GrPixelConfig) const;
+
+    /**
+     * Can non-power-of-two textures be used with tile modes other than clamp?
+     */
+    bool npotTextureTileSupport() const;
 
     /**
      *  Return the max width or height of a texture supported by the current GPU.