Convert string16 to base::string16 in content.

content/public/browser/render_widget_host.h

Index: content/public/browser/render_widget_host.h
diff --git a/content/public/browser/render_widget_host.h b/content/public/browser/render_widget_host.h
index 25fa41eaed9c7cff868052ef28b9727b3e563a14..944ecbbcc757b63f6ea640420626994e1e60c84c 100644
--- a/content/public/browser/render_widget_host.h
+++ b/content/public/browser/render_widget_host.h
@@ -256,11 +256,11 @@ class CONTENT_EXPORT RenderWidgetHost : public IPC::Sender {
 
   // Makes an IPC call to tell webkit to replace the currently selected word
   // or a word around the cursor.
-  virtual void Replace(const string16& word) = 0;
+  virtual void Replace(const base::string16& word) = 0;
 
   // Makes an IPC call to tell webkit to replace the misspelling in the current
   // selection.
-  virtual void ReplaceMisspelling(const string16& word) = 0;
+  virtual void ReplaceMisspelling(const base::string16& word) = 0;
 
   // Called to notify the RenderWidget that the resize rect has changed without
   // the size of the RenderWidget itself changing.