add break statement -- lost during rewrite earlier

BUG=skia:
TBR=

Review URL: https://codereview.chromium.org/1193333004

src/core/SkPictureData.cpp

@@ -541,6 +541,7 @@ bool SkPictureData::parseBufferTag(SkReadBuffer& buffer, uint32_t tag, uint32_t
                                        create_picture_from_buffer)) {
                 return false;
             }
+            break;
         default:
             // The tag was invalid.
             return false;