Add UMA statistics to the clipboard

content/browser/browser_context.cc

 // 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.
 
 #include "content/public/browser/browser_context.h"
 
 #if !defined(OS_IOS)
 #include "base/path_service.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/dom_storage/dom_storage_context_impl.h"
@@ skipping 96 matching lines @@
   }
 
   ui::Clipboard::SourceTag GetAsSourceTag() {
     return ui::Clipboard::SourceTag(this);
   }
 
  private:
   void ExamineClipboard(ui::Clipboard* clipboard,
                         ui::Clipboard::Buffer buffer) {
     ui::Clipboard::SourceTag source_tag = clipboard->ReadSourceTag(buffer);
-    if (source_tag == ui::Clipboard::SourceTag(this))
-      clipboard->Clear(buffer);
+    if (source_tag == ui::Clipboard::SourceTag(this)) {
+      if (buffer == ui::Clipboard::BUFFER_STANDARD) {
+        // We want to leave invalid SourceTag in the clipboard in order to
+        // collect statistics later.
+        clipboard->WriteObjects(buffer,
+                                ui::Clipboard::ObjectMap(),
+                                ui::Clipboard::kInvalidSourceTag);
+      } else {
+        clipboard->Clear(buffer);
+      }
+    }
   }
 };
 
 // Returns existing OffTheRecordClipboardDestroyer or creates one.
 OffTheRecordClipboardDestroyer* GetClipboardDestroyerForBrowserContext(
     BrowserContext* context) {
   if (base::SupportsUserData::Data* data = context->GetUserData(
           kClipboardDestroyerKey))
     return static_cast<OffTheRecordClipboardDestroyer*>(data);
   OffTheRecordClipboardDestroyer* data = new OffTheRecordClipboardDestroyer;
@@ skipping 196 matching lines @@
 #endif  // !OS_IOS
 
 BrowserContext::~BrowserContext() {
 #if !defined(OS_IOS)
   if (GetUserData(kDownloadManagerKeyName))
     GetDownloadManager(this)->Shutdown();
 #endif
 }
 
 }  // namespace content