call onGetUPEM to subclasses can optimize it, and place default behavior

trunk/src/core/SkTypeface.cpp

Index: trunk/src/core/SkTypeface.cpp
===================================================================
--- trunk/src/core/SkTypeface.cpp	(revision 8293)
+++ trunk/src/core/SkTypeface.cpp	(working copy)
@@ -132,32 +132,33 @@
 }
 
 int SkTypeface::getUnitsPerEm() const {
+    // should we try to cache this in the base-class?
+    return this->onGetUPEM();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkFontDescriptor.h"
+
+int SkTypeface::onGetUPEM() const {
     int upem = 0;
 
-#ifdef SK_BUILD_FOR_ANDROID
-    upem = SkFontHost::GetUnitsPerEm(fUniqueID);
-#else
     SkAdvancedTypefaceMetrics* metrics;
     metrics = this->getAdvancedTypefaceMetrics(
-                                 SkAdvancedTypefaceMetrics::kNo_PerGlyphInfo,
-                                 NULL, 0);
+                             SkAdvancedTypefaceMetrics::kNo_PerGlyphInfo,
+                             NULL, 0);
     if (metrics) {
         upem = metrics->fEmSize;
         metrics->unref();
     }
-#endif
     return upem;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-///////////////////////////////////////////////////////////////////////////////
-
-#include "SkFontDescriptor.h"
-
-int SkTypeface::onGetUPEM() const { return 0; }
 int SkTypeface::onGetTableTags(SkFontTableTag tags[]) const { return 0; }
 size_t SkTypeface::onGetTableData(SkFontTableTag, size_t offset,
                                   size_t length, void* data) const { return 0; }
 void SkTypeface::onGetFontDescriptor(SkFontDescriptor* desc) const {
     desc->setStyle(this->style());
 }
+