Extend WebSurroundingText to accept a WebRange.

public/web/WebSurroundingText.h

Index: public/web/WebSurroundingText.h
diff --git a/public/web/WebSurroundingText.h b/public/web/WebSurroundingText.h
index aa6e268faa55b6a637c2972d5f3bd50b081054b1..b5abbc834620bc1be8f93886c81edfee707e1a2b 100644
--- a/public/web/WebSurroundingText.h
+++ b/public/web/WebSurroundingText.h
@@ -38,8 +38,11 @@ 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() { }
@@ -48,17 +51,34 @@ public:
     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: