PDF: Add UMA to track embedded PDF triggered drive-by downloads.

chrome/browser/download/chrome_download_manager_delegate.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 CHROME_BROWSER_DOWNLOAD_CHROME_DOWNLOAD_MANAGER_DELEGATE_H_
 #define CHROME_BROWSER_DOWNLOAD_CHROME_DOWNLOAD_MANAGER_DELEGATE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 103 matching lines @@
                            DownloadConfirmationReason reason,
                            const ConfirmationCallback& callback) override;
   void DetermineLocalPath(content::DownloadItem* download,
                           const base::FilePath& virtual_path,
                           const LocalPathCallback& callback) override;
   void CheckDownloadUrl(content::DownloadItem* download,
                         const base::FilePath& suggested_virtual_path,
                         const CheckDownloadUrlCallback& callback) override;
   void GetFileMimeType(const base::FilePath& path,
                        const GetFileMimeTypeCallback& callback) override;
+  void RecordDriveByPDFDownload() const override;
 
   // So that test classes that inherit from this for override purposes
   // can call back into the DownloadManager.
   content::DownloadManager* download_manager_;
 
  private:
   friend class base::RefCountedThreadSafe<ChromeDownloadManagerDelegate>;
   FRIEND_TEST_ALL_PREFIXES(ChromeDownloadManagerDelegateTest,
                            RequestConfirmation_Android);
 
@@ skipping 42 matching lines @@
 #endif
 
   content::NotificationRegistrar registrar_;
 
   base::WeakPtrFactory<ChromeDownloadManagerDelegate> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeDownloadManagerDelegate);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_CHROME_DOWNLOAD_MANAGER_DELEGATE_H_