Cache the GrEffect used for text rendering in GrBitmapTextContext.

src/gpu/GrBitmapTextContext.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrBitmapTextContext_DEFINED
 #define GrBitmapTextContext_DEFINED
 
@@ skipping 27 matching lines @@
     void flushGlyphs();                 // automatically called by destructor
     void finish();
 
     enum {
         kMinRequestedGlyphs      = 1,
         kDefaultRequestedGlyphs  = 64,
         kMinRequestedVerts       = kMinRequestedGlyphs * 4,
         kDefaultRequestedVerts   = kDefaultRequestedGlyphs * 4,
     };
 
-    void*                   fVertices;
-    int32_t                 fMaxVertices;
-    GrTexture*              fCurrTexture;
-    int                     fCurrVertex;
-    SkRect                  fVertexBounds;
+    void*                       fVertices;
+    int32_t                     fMaxVertices;
+    GrTexture*                  fCurrTexture;
+    SkAutoTUnref<GrEffectRef>   fCachedEffect;
+    uint32_t                    fEffectTextureGenID;
+    int                         fCurrVertex;
+    SkRect                      fVertexBounds;
 };
 
 #endif