Omnibox - ClipboardRecentContent - Make Proper Singleton

components/open_from_clipboard/clipboard_recent_content.h

Index: components/open_from_clipboard/clipboard_recent_content.h
diff --git a/components/open_from_clipboard/clipboard_recent_content.h b/components/open_from_clipboard/clipboard_recent_content.h
index e7d55e92e1d3811e1f45c38d8e4a299c68fd8301..564e640d2b96919ff7ea8f625be8b34be2369d3c 100644
--- a/components/open_from_clipboard/clipboard_recent_content.h
+++ b/components/open_from_clipboard/clipboard_recent_content.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_OPEN_FROM_CLIPBOARD_CLIPBOARD_RECENT_CONTENT_H_
 #define COMPONENTS_OPEN_FROM_CLIPBOARD_CLIPBOARD_RECENT_CONTENT_H_
 
+#include <memory>
 #include <string>
 
 #include "base/macros.h"
@@ -25,7 +26,7 @@ class ClipboardRecentContent {
   static ClipboardRecentContent* GetInstance();
 
   // Sets the global instance of ClipboardRecentContent singleton.
-  static void SetInstance(ClipboardRecentContent* instance);
+  static void SetInstance(std::unique_ptr<ClipboardRecentContent> instance);
 
   // Returns true if the clipboard contains a recent URL that is appropriate to
   // be suggested and has not been supressed, and copies it in |url|.
@@ -48,6 +49,10 @@ class ClipboardRecentContent {
   static bool IsAppropriateSuggestion(const GURL& url);
 
  private:
+  // Returns the address of the unique_ptr that stores the current global
+  // ClipboardRecentContent used in GetInstance() / SetInstance().
+  static std::unique_ptr<ClipboardRecentContent>* UniquePtrToInstance();
+
   DISALLOW_COPY_AND_ASSIGN(ClipboardRecentContent);
 };