Add BW masks to random scaler context

src/fonts/SkRandomScalerContext.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRandomScalerContext.h"
 #include "SkGlyph.h"
 #include "SkPath.h"
@@ skipping 45 matching lines @@
 }
 
 void SkRandomScalerContext::generateAdvance(SkGlyph* glyph) {
     fProxy->getAdvance(glyph);
 }
 
 void SkRandomScalerContext::generateMetrics(SkGlyph* glyph) {
     // Here we will change the mask format of the glyph
     // NOTE this is being overridden by the base class
     SkMask::Format format;
-    switch (glyph->getGlyphID() % 3) {
+    switch (glyph->getGlyphID() % 4) {
         case 0:
             format = SkMask::kLCD16_Format;
             break;
         case 1:
             format = SkMask::kA8_Format;
             break;
         case 2:
             format = SkMask::kARGB32_Format;
             break;
+        case 3:
+            format = SkMask::kBW_Format;
+            break;
     }
 
     fProxy->getMetrics(glyph);
 
     glyph->fMaskFormat = format;
     if (fFakeIt) {
         return;
     }
     if (SkMask::kARGB32_Format == format) {
         SkPath path;
@@ skipping 39 matching lines @@
                 break;
             default:
                 break;
             }
         }
     }
 }
 
 void SkRandomScalerContext::generateImage(const SkGlyph& glyph) {
     SkMask::Format format = (SkMask::Format)glyph.fMaskFormat;
-    switch (glyph.getGlyphID() % 3) {
+    switch (glyph.getGlyphID() % 4) {
         case 0:
             format = SkMask::kLCD16_Format;
             break;
         case 1:
             format = SkMask::kA8_Format;
             break;
         case 2:
             format = SkMask::kARGB32_Format;
             break;
+        case 3:
+            format = SkMask::kBW_Format;
+            break;
     }
     const_cast<SkGlyph&>(glyph).fMaskFormat = format;
 
     // if the format is ARGB, we just draw the glyph from path ourselves.  Otherwise, we force
     // our proxy context to generate the image from paths.
     if (!fFakeIt) {
         if (SkMask::kARGB32_Format == glyph.fMaskFormat) {
             SkPath path;
             fProxy->getPath(glyph, &path);
 
@@ skipping 88 matching lines @@
 
 int SkRandomTypeface::onGetTableTags(SkFontTableTag tags[]) const {
     return fProxy->getTableTags(tags);
 }
 
 size_t SkRandomTypeface::onGetTableData(SkFontTableTag tag, size_t offset,
                                     size_t length, void* data) const {
     return fProxy->getTableData(tag, offset, length, data);
 }