Simple patch to have draw path call an internal drawPath

The purpose of this patch is to expose an internal draw path call which text contexts can use.

BUG=skia:

Review URL: https://codereview.chromium.org/1012143005
diff --git a/src/gpu/SkGpuDevice.h b/src/gpu/SkGpuDevice.h
index 50aa586..af6dd0b 100644
--- a/src/gpu/SkGpuDevice.h
+++ b/src/gpu/SkGpuDevice.h
@@ -199,6 +199,10 @@
                          int tileSize,
                          bool bicubic);
 
+    void internalDrawPath(const SkPath& origSrcPath, const SkPaint& paint,
+                          const SkMatrix& origViewMatrix, const SkMatrix* prePathMatrix,
+                          const SkIRect& clipBounds, bool pathIsMutable);
+
     bool drawDashLine(const SkPoint pts[2], const SkPaint& paint);
 
     static SkPicture::AccelData::Key ComputeAccelDataKey();