Conservative SkTextBlob bounds.

include/core/SkTextBlob.h

Index: include/core/SkTextBlob.h
diff --git a/include/core/SkTextBlob.h b/include/core/SkTextBlob.h
index 334cfb98c4595d2d51844e55c82880b89de9a34e..1f04d3891278e42ae24452f21ecc57a428119426 100644
--- a/include/core/SkTextBlob.h
+++ b/include/core/SkTextBlob.h
@@ -23,7 +23,7 @@ class SkWriteBuffer;
 class SK_API SkTextBlob : public SkRefCnt {
 public:
     /**
-     *  Returns the blob bounding box.
+     *  Returns a conservative blob bounding box.
      */
     const SkRect& bounds() const { return fBounds; }
 
@@ -188,6 +188,9 @@ private:
                   int count, SkPoint offset);
     void updateDeferredBounds();
 
+    static SkRect ConservativeRunBounds(const SkTextBlob::RunRecord&);
+    static SkRect TightRunBounds(const SkTextBlob::RunRecord&);
+
     SkAutoTMalloc<uint8_t> fStorage;
     size_t                 fStorageSize;
     size_t                 fStorageUsed;