Font variations.

include/core/SkTypeface.h

Index: include/core/SkTypeface.h
diff --git a/include/core/SkTypeface.h b/include/core/SkTypeface.h
index 6a6d7241a2c861a1268ef992b5d87ed7b652d379..1fb9ef70e425a3a1c3a0017cbcfa6e041d3e7ed6 100644
--- a/include/core/SkTypeface.h
+++ b/include/core/SkTypeface.h
@@ -16,6 +16,7 @@
 #include "SkWeakRefCnt.h"
 
 class SkDescriptor;
+class SkFontData;
 class SkFontDescriptor;
 class SkScalerContext;
 struct SkScalerContextRec;
@@ -133,6 +134,12 @@ public:
     */
     static SkTypeface* CreateFromStream(SkStreamAsset* stream, int index = 0);
 
+    /** Return a new typeface given font data and configuration. If the data
+        is not valid font data, returns null. Ownership of the stream is

[reed1, 2015/05/08 20:46:30]

ownership of the data?

[bungeman-skia, 2015/05/11 22:09:35]

Right now the caller retains ownership of the SkFontData*, but after this call
the stream (if any) on the SkFontData* will have been detached and the callee
now owns the stream (either my storing it or deleting it). This is a bit
confusing. The reason this works at the moment is because the stream is the only
thing big and a pointer to a long lived thing, so essentially the stream is
moved, but the rest is copied. I think the idea is that the user could just put
a SkFontData on the stack and have passed its address, but they're not allowed
to have done that with the stream. I'm already requiring an asset stream here,
so we could duplicate it in this case, but that seems like extra work that isn't
usually needed.

I can, of course, explain this better in the comment, but this sort of thing is
what I'm most concerned about anyway. I'll have to see if there is a cleaner way
of doing this (which also allows fewer copies of information to begin with, like
the axis data which is copied like three times in the Android case).

This is just a helper function to call the associated method on SkFontMgr, so
the same goes for that method.

+        transferred, so the caller must not reference it again.
+    */
+    static SkTypeface* CreateFromFontData(SkFontData*);
+
     /** Write a unique signature to a stream, sufficient to reconstruct a
         typeface referencing the same font when Deserialize is called.
      */
@@ -281,6 +288,7 @@ public:
      *  The caller is responsible for deleting the stream.
      */
     SkStreamAsset* openStream(int* ttcIndex) const;
+    SkFontData* createFontData() const;
 
     /**
      *  Return a scalercontext for the given descriptor. If this fails, then
@@ -326,6 +334,9 @@ protected:
                         uint32_t glyphIDsCount) const = 0;
 
     virtual SkStreamAsset* onOpenStream(int* ttcIndex) const = 0;
+    // TODO: make pure virtual.
+    virtual SkFontData* onCreateFontData() const;
+
     virtual void onGetFontDescriptor(SkFontDescriptor*, bool* isLocal) const = 0;
 
     virtual int onCharsToGlyphs(const void* chars, Encoding, uint16_t glyphs[],