simple patch to always init SkTextBlob uniqueID

include/core/SkTextBlob.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTextBlob_DEFINED
 #define SkTextBlob_DEFINED
 
@@ skipping 12 matching lines @@
 class SK_API SkTextBlob : public SkRefCnt {
 public:
     /**
      *  Returns a conservative blob bounding box.
      */
     const SkRect& bounds() const { return fBounds; }
 
     /**
      *  Return a non-zero, unique value representing the text blob.
      */
-    uint32_t uniqueID() const;
+    uint32_t uniqueID() const { return fUniqueID; }
 
     /**
      *  Serialize to a buffer.
      */
     void flatten(SkWriteBuffer&) const;
 
     /**
      *  Recreate an SkTextBlob that was serialized into a buffer.
      *
      *  @param  SkReadBuffer Serialized blob data.
@@ skipping 47 matching lines @@
 
     static unsigned ScalarsPerGlyph(GlyphPositioning pos);
 
     friend class GrTextContext;
     friend class SkBaseDevice;
     friend class SkTextBlobBuilder;
     friend class TextBlobTester;
 
     const int        fRunCount;
     const SkRect     fBounds;
-    mutable uint32_t fUniqueID;
+    const uint32_t fUniqueID;
 
     SkDEBUGCODE(size_t fStorageSize;)
 
     // The actual payload resides in externally-managed storage, following the object.
     // (see the .cpp for more details)
 
     typedef SkRefCnt INHERITED;
 };
 
 /** \class SkTextBlobBuilder
@@ skipping 86 matching lines @@
 
     SkRect                 fBounds;
     int                    fRunCount;
     bool                   fDeferredBounds;
     size_t                 fLastRun; // index into fStorage
 
     RunBuffer              fCurrentRunBuffer;
 };
 
 #endif // SkTextBlob_DEFINED