Make glyph cache more flexible

Some GPU architectures could not handle the previous implementation
of our glyph cache. Frequent uploads would cause memory problems in the GPU
and eventually a crash due to these memory issues. The solution is to move to
a system of several, smaller caches instead of one monolythic cache for all
glyphs.

Change-Id: I0fc7a323360940d16d5a33eeb33abfab194c5920
diff --git a/libs/hwui/GammaFontRenderer.h b/libs/hwui/GammaFontRenderer.h
index 54c208e..99f08f0 100644
--- a/libs/hwui/GammaFontRenderer.h
+++ b/libs/hwui/GammaFontRenderer.h
@@ -50,7 +50,7 @@
         FontRenderer* renderer = mRenderers[fontRenderer];
         if (!renderer) return 0;
 
-        return renderer->getCacheHeight() * renderer->getCacheWidth();
+        return renderer->getCacheSize();
     }
 
 private: