combine glyph and image bulk alloc, and adjust initial alloc size, to reduce total waste from 50% t…

include/core/SkChunkAlloc.h

Index: include/core/SkChunkAlloc.h
diff --git a/include/core/SkChunkAlloc.h b/include/core/SkChunkAlloc.h
index 1b52a35c16c0000c8611c8828c60097a217ad266..e13e2b99c640368ebfbdc5f3e16f6e47f3620807 100644
--- a/include/core/SkChunkAlloc.h
+++ b/include/core/SkChunkAlloc.h
@@ -42,6 +42,7 @@ public:
     size_t unalloc(void* ptr);
 
     size_t totalCapacity() const { return fTotalCapacity; }
+    size_t totalUsed() const { return fTotalUsed; }
     int blockCount() const { return fBlockCount; }
 
     /**
@@ -58,6 +59,7 @@ private:
     size_t  fMinSize;
     size_t  fChunkSize;
     size_t  fTotalCapacity;
+    size_t  fTotalUsed;     // will be <= fTotalCapacity
     int     fBlockCount;
 
     Block* newBlock(size_t bytes, AllocFailType ftype);