Add an interface to gather text surrounding the selection.

content/browser/android/text_surroundings_delegate.h

+// Delegate for receiving a response containing text surrounding the selection.
+
+#ifndef CONTENT_BROWSER_ANDROID_TEXT_SURROUNDINGS_DELEGATE_H_
+#define CONTENT_BROWSER_ANDROID_TEXT_SURROUNDINGS_DELEGATE_H_
+
+namespace content {
+
+// Defines an interface for a delegate to receive text that surrounds the
+// selection.
+class TextSurroundingsDelegate {
+ public:
+  virtual void OnTextSurroundingSelectionResponse(const base::string16& content,
+                                                  int start_offset,
+                                                  int end_offset) = 0;
+ protected:

[jdduke (slow), 2014/06/10 22:08:09]

This should probably go in the content/public/android folder where
content_view_core.h lives. We may also need a |OnContentViewDestroyed()| method
so the delegate doesn't hold any dangling references, OR you could have a
|SetContentViewCore()| that gets called when the delegate is assigned to the
ContentViewCore (and called with NULL when the ContentViewCore is destroyed).

[donnd, 2014/06/17 22:23:25]

Done.

Looks like the delegate never holds on to the ContentViewCore, so we don't need
to notify the delegate when the ContentViewCore goes away.  Also, when the
ContentViewCore goes away, it will just drop its pointer to the delegate, so we
don't even need to NULL or destroy that pointer.  Does that sound right to you?

+  virtual ~TextSurroundingsDelegate() {}
+};
+
+}  // namespace content
+#endif  // CONTENT_BROWSER_ANDROID_TEXT_SURROUNDINGS_DELEGATE_H_