Add SkTypeface* parameter to SkScalerContext (and its callers)

trunk/include/core/SkTypeface.h

Index: trunk/include/core/SkTypeface.h
===================================================================
--- trunk/include/core/SkTypeface.h	(revision 8215)
+++ trunk/include/core/SkTypeface.h	(working copy)
@@ -194,6 +194,7 @@
     int getUnitsPerEm() const;
 
     SkStream* openStream(int* ttcIndex) const;
+    SkScalerContext* createScalerContext(const SkDescriptor*) const;
 
 protected:
     /** uniqueID must be unique and non-zero
@@ -218,6 +219,7 @@
     bool        fIsFixedWidth;
 
     friend class SkPaint;
+    friend class SkGlyphCache;  // GetDefaultTypeface
     // just so deprecated fonthost can call protected methods
     friend class SkFontHost;