Extend WebSurroundingText to accept a WebRange.

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 20 matching lines @@
 #include "WebRange.h"
 
 namespace WebCore {
 class SurroundingText;
 }
 
 namespace blink {
 
 class WebHitTestResult;
 class WebNode;
+class WebRange;
 struct WebPoint;
 
+// WebSurroundingText is a Blink API that gives access to the SurroundingText
+// API. It allows caller to know the text surrounding a point or a range.
 class WebSurroundingText {
 public:
     WebSurroundingText() { }
     ~WebSurroundingText() { reset(); }
 
     BLINK_EXPORT bool isNull() const;
     BLINK_EXPORT void reset();
 
-    // Initializes the object to get the surrounding text centered in the position relative to a provided node.
+    // Initializes the object to get the surrounding text centered in the
+    // position relative to a provided node.
     // The maximum length of the contents retrieved is defined by maxLength.
     BLINK_EXPORT void initialize(const WebNode&, const WebPoint&, size_t maxLength);
 
+    // Initializes the object to get the text surrounding a given range.
+    // The maximum length of the contents retrieved is defined by maxLength.
+    // It does not include the text inside the range.
+    BLINK_EXPORT void initialize(const WebRange&, size_t maxLength);
+
     // Surrounding text content retrieved.
     BLINK_EXPORT WebString textContent() const;
 
-    // Offset in the text content of the initial hit position (or provided offset in the node).
+    // Offset in the text content of the initial hit position (or provided
+    // offset in the node).
+    // This should only be called when WebSurroundingText has been initialized
+    // with a WebPoint.
+    // DEPRECATED: use startOffsetInTextContent() or endOffsetInTextContent().
     BLINK_EXPORT size_t hitOffsetInTextContent() const;
 
-    // Convert start/end positions in the content text string into a WebKit text range.
+    // 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:
     WebPrivateOwnPtr<WebCore::SurroundingText> m_private;
 };
 
 } // namespace blink
 
 #endif