fix casting issue with or operator

include/core/SkCanvas.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCanvas_DEFINED
 #define SkCanvas_DEFINED
 
@@ skipping 1496 matching lines @@
 
 private:
     SkBitmap    fBitmap;    // used if peekPixels() fails
     const void* fAddr;      // NULL on failure
     SkImageInfo fInfo;
     size_t      fRowBytes;
 };
 
 static inline SkCanvas::SaveFlags operator|(const SkCanvas::SaveFlags lhs,
                                             const SkCanvas::SaveFlags rhs) {
-    return static_cast<SkCanvas::SaveFlags>(lhs | rhs);
+    return static_cast<SkCanvas::SaveFlags>(static_cast<int>(lhs) | static_cast<int>(rhs));
 }
 
 static inline SkCanvas::SaveFlags& operator|=(SkCanvas::SaveFlags& lhs,
                                               const SkCanvas::SaveFlags rhs) {
     lhs = lhs | rhs;
     return lhs;
 }
 
 
 #endif