Add UMA statistics to the clipboard

ui/base/clipboard/clipboard.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_BASE_CLIPBOARD_CLIPBOARD_H_
 #define UI_BASE_CLIPBOARD_CLIPBOARD_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 155 matching lines @@
   //               size         gfx::Size struct
   // CBF_DATA      format       char array
   //               data         byte array
   typedef std::vector<char> ObjectMapParam;
   typedef std::vector<ObjectMapParam> ObjectMapParams;
   typedef std::map<int /* ObjectType */, ObjectMapParams> ObjectMap;
 
   // WriteObject() caller can use the SourceTag that will be stored in the
   // clipboard. NULL value means "no tag".
   typedef void* SourceTag;
+  // kInvalidSourceTag is not NULL but a special value != any pointer.
+  static const SourceTag kInvalidSourceTag;
   static ObjectMapParam SourceTag2Binary(SourceTag tag);
   static SourceTag Binary2SourceTag(const std::string& serialization);
 
   // Buffer designates which clipboard the action should be applied to.
   // Only platforms that use the X Window System support the selection
   // buffer.
   enum Buffer {
     BUFFER_STANDARD,
     BUFFER_SELECTION,
   };
@@ skipping 162 matching lines @@
 
   void WriteWebSmartPaste();
 
   void WriteBitmap(const char* pixel_data, const char* size_data);
 
   void WriteData(const FormatType& format,
                  const char* data_data,
                  size_t data_len);
 
   void WriteSourceTag(SourceTag tag);
+
+  enum TrackedAction {
+    WRITE_CLIPBOARD_NO_SOURCE_TAG,
+    WRITE_CLIPBOARD_SOURCE_TAG,
+    READ_TEXT,
+    MAX_TRACKED_ACTION,
+  };
+
+  void ReportAction(Buffer buffer, TrackedAction action) const;
 #if defined(OS_WIN)
   void WriteBitmapFromHandle(HBITMAP source_hbitmap,
                              const gfx::Size& size);
 
   // Safely write to system clipboard. Free |handle| on failure.
   void WriteToClipboard(unsigned int format, HANDLE handle);
 
   static void ParseBookmarkClipboardFormat(const string16& bookmark,
                                            string16* title,
                                            std::string* url);
@@ skipping 50 matching lines @@
   scoped_ptr<AuraX11Details> aurax11_details_;
 #endif
   base::Callback<void(Buffer)> write_objects_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Clipboard);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_CLIPBOARD_CLIPBOARD_H_