Remove the use of WebRange in ContentDetector.

third_party/WebKit/public/web/WebSurroundingText.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 54 matching lines @@
     // with a WebPoint.
     // DEPRECATED: use startOffsetInTextContent() or endOffsetInTextContent().
     BLINK_EXPORT size_t hitOffsetInTextContent() const;
 
     // Start offset of the initial text in the text content.
     BLINK_EXPORT size_t startOffsetInTextContent() const;
 
     // End offset of the initial text in the text content.
     BLINK_EXPORT size_t endOffsetInTextContent() const;
 
-    // Convert start/end positions in the content text string into a WebKit text
-    // range.
-    BLINK_EXPORT WebRange rangeFromContentOffsets(size_t startOffsetInContent, size_t endOffsetInContent);
-
 protected:
     std::unique_ptr<SurroundingText> m_private;
 };
 
 } // namespace blink
 
 #endif