Add needed virtual destructors.

src/ports/SkRemotableFontMgr_win_dw.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDataTable.h"
 #include "SkDWrite.h"
 #include "SkDWriteFontFileStream.h"
@@ skipping 272 matching lines @@
         return this->matchIndexStyle(index, style);
     }
 
     class FontFallbackRenderer : public IDWriteTextRenderer {
     public:
         FontFallbackRenderer(const SkRemotableFontMgr_DirectWrite* outer, UINT32 character)
             : fRefCount(1), fOuter(SkSafeRef(outer)), fCharacter(character) {
           fIdentity.fDataId = SkFontIdentity::kInvalidDataId;
         }
 
+        virtual ~FontFallbackRenderer() { }
+
         // IDWriteTextRenderer methods
         virtual HRESULT STDMETHODCALLTYPE DrawGlyphRun(
             void* clientDrawingContext,
             FLOAT baselineOriginX,
             FLOAT baselineOriginY,
             DWRITE_MEASURING_MODE measuringMode,
             DWRITE_GLYPH_RUN const* glyphRun,
             DWRITE_GLYPH_RUN_DESCRIPTION const* glyphRunDescription,
             IUnknown* clientDrawingEffect) SK_OVERRIDE
         {
@@ skipping 213 matching lines @@
     } else {
         localeNameLen = getUserDefaultLocaleNameProc(localeNameStorage, LOCALE_NAME_MAX_LENGTH);
         if (localeNameLen) {
             localeName = localeNameStorage;
         };
     }
 
     return SkNEW_ARGS(SkRemotableFontMgr_DirectWrite, (sysFontCollection.get(),
                                                        localeName, localeNameLen));
 }