Stop overloading internal_dispose in SkTextBlob and SkData

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 61 matching lines @@
     private:
         const RunRecord* fCurrentRun;
         int              fRemainingRuns;
 
         SkDEBUGCODE(uint8_t* fStorageTop;)
     };
 
     SkTextBlob(int runCount, const SkRect& bounds);
 
     virtual ~SkTextBlob();
-    virtual void internal_dispose() const SK_OVERRIDE;
+
+    // Memory for objects of this class is created with sk_malloc rather than operator new and must
+    // be freed with sk_free.
+    void operator delete(void* p) { sk_free(p); }
+    void* operator new(size_t) {
+        SkFAIL("All blobs are created by placement new.");
+        return sk_malloc_throw(0);
+    }
+    void* operator new(size_t, void* p) { return p; }
 
     static unsigned ScalarsPerGlyph(GlyphPositioning pos);
 
     friend class SkBaseDevice;
     friend class SkTextBlobBuilder;
     friend class TextBlobTester;
 
     const int        fRunCount;
     const SkRect     fBounds;
     mutable uint32_t fUniqueID;
@@ skipping 93 matching lines @@
 
     SkRect                 fBounds;
     int                    fRunCount;
     bool                   fDeferredBounds;
     size_t                 fLastRun; // index into fStorage
 
     RunBuffer              fCurrentRunBuffer;
 };
 
 #endif // SkTextBlob_DEFINED