First pass at drawAtlas batching.

include/gpu/GrDrawContext.h

Index: include/gpu/GrDrawContext.h
diff --git a/include/gpu/GrDrawContext.h b/include/gpu/GrDrawContext.h
index 4d59b8cd9deaa5787c82529f5e2255207b0ae4d1..7811f6c45f2683a21b499b3aa56f3aa187e074e2 100644
--- a/include/gpu/GrDrawContext.h
+++ b/include/gpu/GrDrawContext.h
@@ -33,6 +33,7 @@ class SkPath;
 struct SkPoint;
 struct SkRect;
 class SkRRect;
+struct SkRSXform;
 class SkTextBlob;
 
 /*
@@ -222,6 +223,26 @@ public:
                       int indexCount);
 
     /**
+     * Draws textured sprites from an atlas with a paint.
+     *
+     * @param   paint           describes how to color pixels.
+     * @param   viewMatrix      transformation matrix
+     * @param   spriteCount     number of sprites.
+     * @param   xform           array of compressed transformation data, required.

[robertphillips, 2015/08/07 16:12:37]

'access the atlas' ?

+     * @param   texRect         array of texture rectangles used to access the paint.

[robertphillips, 2015/08/07 16:12:37]

'per sprite' ?

+     * @param   colors          optional array of per-vertex colors, supercedes
+     *                          the paint's color field.
+     */
+    void drawAtlas(GrRenderTarget*,
+                   const GrClip&,
+                   const GrPaint& paint,
+                   const SkMatrix& viewMatrix,
+                   int spriteCount,
+                   const SkRSXform xform[],
+                   const SkRect texRect[],
+                   const SkColor colors[]);
+    
+    /**
      * Draws an oval.
      *
      * @param paint         describes how to color pixels.