In SkGPipe, only serialize SkTypefaces in cross process mode.

In SkGPipe, only serialize SkTypefaces in cross process mode.

Also make SkGPipeController ref the recording canvas to ensure that
objects used by SkGPipeCanvas (e.g. SharedHeap and fTypefaceSet, which
hold references to objects to which pointers are written to the stream)
survive to be played back even if SkGPipeWriter.endRecording() is called.

BUG=
TEST=TypefaceGM

Review URL: https://codereview.appspot.com/6447055

git-svn-id: http://skia.googlecode.com/svn/trunk@4817 2bbb7eff-a529-9590-31e7-b0007b416f81