Revert of Implement ui::ClipboardMus.

ui/base/clipboard/clipboard.h

Index: ui/base/clipboard/clipboard.h
diff --git a/ui/base/clipboard/clipboard.h b/ui/base/clipboard/clipboard.h
index 7826b2696df33c824865ea9caf85446bebb35153..40af4df4f2fe2d1568227ee242f4118648c67d53 100644
--- a/ui/base/clipboard/clipboard.h
+++ b/ui/base/clipboard/clipboard.h
@@ -9,7 +9,6 @@
 #include <stdint.h>
 
 #include <map>
-#include <memory>
 #include <string>
 #include <vector>
 
@@ -61,13 +60,9 @@
   static const char kMimeTypeText[];
   static const char kMimeTypeURIList[];
   static const char kMimeTypeDownloadURL[];
-  static const char kMimeTypeMozillaURL[];
   static const char kMimeTypeHTML[];
   static const char kMimeTypeRTF[];
   static const char kMimeTypePNG[];
-  static const char kMimeTypeWebCustomData[];
-  static const char kMimeTypeWebkitSmartPaste[];
-  static const char kMimeTypePepperCustomData[];
 
   // Platform neutral holder for native data representation of a clipboard type.
   struct UI_BASE_EXPORT FormatType {
@@ -141,13 +136,6 @@
   // Sets the list of threads that are allowed to access the clipboard.
   static void SetAllowedThreads(
       const std::vector<base::PlatformThreadId>& allowed_threads);
-
-  // Sets the clipboard for the current thread. Previously, there was only
-  // one clipboard implementation on a platform; now that mus exists, during
-  // mus app startup, we need to specifically initialize mus instead of the
-  // current platform clipboard. We take ownership of |platform_clipboard|.
-  static void SetClipboardForCurrentThread(
-      std::unique_ptr<Clipboard> platform_clipboard);
 
   // Returns the clipboard object for the current thread.
   //
@@ -320,13 +308,8 @@
 
  private:
   // For access to WriteObjects().
-  friend class ForwardingTestingClipboard;
   friend class ScopedClipboardWriter;
   friend class TestClipboard;
-  // For SetClipboardForCurrentThread's argument.
-  friend struct std::default_delete<Clipboard>;
-
-  static base::PlatformThreadId GetAndValidateThreadID();
 
   // A list of allowed threads. By default, this is empty and no thread checking
   // is done (in the unit test case), but a user (like content) can set which
@@ -335,8 +318,7 @@
   static base::LazyInstance<AllowedThreadsVector> allowed_threads_;
 
   // Mapping from threads to clipboard objects.
-  typedef std::map<base::PlatformThreadId, std::unique_ptr<Clipboard>>
-      ClipboardMap;
+  typedef std::map<base::PlatformThreadId, Clipboard*> ClipboardMap;
   static base::LazyInstance<ClipboardMap> clipboard_map_;
 
   // Mutex that controls access to |g_clipboard_map|.