Refactor GammaFontRenderer

This change is the first step to a shader-based text antialias
gamma correction.

Change-Id: I9eb02d4c56cb95d05219f712290c865b46141954
diff --git a/libs/hwui/Caches.h b/libs/hwui/Caches.h
index f83e291..5e09d94 100644
--- a/libs/hwui/Caches.h
+++ b/libs/hwui/Caches.h
@@ -249,9 +249,10 @@
     PatchCache patchCache;
     TextDropShadowCache dropShadowCache;
     FboCache fboCache;
-    GammaFontRenderer fontRenderer;
     ResourceCache resourceCache;
 
+    GammaFontRenderer* fontRenderer;
+
     // Debug methods
     PFNGLINSERTEVENTMARKEREXTPROC eventMark;
     PFNGLPUSHGROUPMARKEREXTPROC startMark;
@@ -261,6 +262,7 @@
     PFNGLGETOBJECTLABELEXTPROC getLabel;
 
 private:
+    void initFont();
     void initExtensions();
     void initConstraints();