Don't try to render color fonts using distance fields

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"
@@ skipping 314 matching lines @@
 
         // alloc storage for distance field glyph
         size_t dfSize = dfWidth * dfHeight * bytesPerPixel;
         SkAutoSMalloc<1024> dfStorage(dfSize);
 
         if (1 == bytesPerPixel) {
             (void) SkGenerateDistanceFieldFromImage((unsigned char*)dfStorage.get(),
                                                     (unsigned char*)storage.get(),
                                                     width, height, DISTANCE_FIELD_RANGE);
         } else {
-            // TODO: Fix color emoji
-            // for now, copy glyph into distance field storage
-            // this is not correct, but it won't crash
-            sk_bzero(dfStorage.get(), dfSize);
-            unsigned char* ptr = (unsigned char*) storage.get();
-            unsigned char* dfPtr = (unsigned char*) dfStorage.get();
-            size_t dfStride = dfWidth*bytesPerPixel;
-            dfPtr += DISTANCE_FIELD_RANGE*dfStride;
-            dfPtr += DISTANCE_FIELD_RANGE*bytesPerPixel;
-
-            for (int i = 0; i < height; ++i) {
-                memcpy(dfPtr, ptr, stride);
-
-                dfPtr += dfStride;
-                ptr += stride;
-            }
+            // distance fields should only be used to represent alpha masks
+            SkASSERT(false);
+            return false;
         }
 
         // copy to atlas
         plot = fAtlasMgr->addToAtlas(&fAtlas, dfWidth, dfHeight, dfStorage.get(),
                                      &glyph->fAtlasLocation);
 
     } else {
         size_t size = glyph->fBounds.area() * bytesPerPixel;
         SkAutoSMalloc<1024> storage(size);
         if (!scaler->getPackedGlyphImage(glyph->fPackedID, glyph->width(),
                                          glyph->height(),
                                          glyph->width() * bytesPerPixel,
                                          storage.get())) {
             return false;
         }
 
         plot = fAtlasMgr->addToAtlas(&fAtlas, glyph->width(),
                                      glyph->height(), storage.get(),
                                      &glyph->fAtlasLocation);
     }
 
     if (NULL == plot) {
         return false;
     }
 
     glyph->fPlot = plot;
     return true;
 }