Implement onCountGlyphs and onGetUPEM on Windows.

src/ports/SkFontHost_win_dw.cpp

Index: src/ports/SkFontHost_win_dw.cpp
===================================================================
--- src/ports/SkFontHost_win_dw.cpp	(revision 10083)
+++ src/ports/SkFontHost_win_dw.cpp	(working copy)
@@ -492,6 +492,8 @@
                                 SkAdvancedTypefaceMetrics::PerGlyphInfo,
                                 const uint32_t*, uint32_t) const SK_OVERRIDE;
     virtual void onGetFontDescriptor(SkFontDescriptor*, bool*) const SK_OVERRIDE;
+    virtual int onCountGlyphs() const SK_OVERRIDE;
+    virtual int onGetUPEM() const SK_OVERRIDE;
 };
 
 class SkScalerContext_Windows : public SkScalerContext {
@@ -1071,6 +1073,16 @@
     *isLocalStream = SkToBool(fDWriteFontFileLoader.get());
 }
 
+int DWriteFontTypeface::onCountGlyphs() const {
+    return fDWriteFontFace->GetGlyphCount();
+}
+
+int DWriteFontTypeface::onGetUPEM() const {
+    DWRITE_FONT_METRICS metrics;
+    fDWriteFontFace->GetMetrics(&metrics);
+    return metrics.designUnitsPerEm;
+}
+
 template <typename T> class SkAutoIDWriteUnregister {
 public:
     SkAutoIDWriteUnregister(IDWriteFactory* factory, T* unregister)