Add CPU backing store for GrAtlas to reduce texture uploads

src/gpu/GrTextStrike.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-#include "GrAtlas.h"
 #include "GrGpu.h"
 #include "GrRectanizer.h"
 #include "GrTextStrike.h"
 #include "GrTextStrike_impl.h"
 #include "SkString.h"
 
 #include "SkDistanceFieldGen.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ skipping 60 matching lines @@
                                           const Key& key) {
     GrMaskFormat format = scaler->getMaskFormat();
     GrPixelConfig config = mask_format_to_pixel_config(format);
     int atlasIndex = mask_format_to_atlas_index(format);
     if (NULL == fAtlasMgr[atlasIndex]) {
         SkISize textureSize = SkISize::Make(GR_ATLAS_TEXTURE_WIDTH,
                                             GR_ATLAS_TEXTURE_HEIGHT);
         fAtlasMgr[atlasIndex] = SkNEW_ARGS(GrAtlasMgr, (fGpu, config,
                                                         textureSize,
                                                         GR_NUM_PLOTS_X,
-                                                        GR_NUM_PLOTS_Y));
+                                                        GR_NUM_PLOTS_Y,
+                                                        true));
     }
     GrTextStrike* strike = SkNEW_ARGS(GrTextStrike,
                                       (this, scaler->getKey(), format, fAtlasMgr[atlasIndex]));
     fCache.insert(key, strike);
 
     if (fHead) {
         fHead->fPrev = strike;
     } else {
         SkASSERT(NULL == fTail);
         fTail = strike;
@@ skipping 220 matching lines @@
                                           glyph->height(), storage.get(),
                                           &glyph->fAtlasLocation);
 
     if (NULL == plot) {
         return false;
     }
 
     glyph->fPlot = plot;
     return true;
 }