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

content/browser/download/download_manager_impl.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/browser/download/download_manager_impl.h"
 
 #include <iterator>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 156 matching lines @@
       const base::FilePath& path,
       const GURL& url,
       const std::string& mime_type,
       std::unique_ptr<DownloadRequestHandleInterface> request_handle,
       const net::NetLogWithSource& net_log) override {
     return new DownloadItemImpl(delegate, download_id, path, url, mime_type,
                                 std::move(request_handle), net_log);
   }
 };
 
+constexpr char kPDFMimeType[] = "application/pdf";
+
 }  // namespace
 
 DownloadManagerImpl::DownloadManagerImpl(net::NetLog* net_log,
                                          BrowserContext* browser_context)
     : item_factory_(new DownloadItemFactoryImpl()),
       file_factory_(new DownloadFileFactory()),
       shutdown_needed_(true),
       browser_context_(browser_context),
       delegate_(nullptr),
       net_log_(net_log),
       weak_factory_(this) {
   DCHECK(browser_context);
 }
 
 DownloadManagerImpl::~DownloadManagerImpl() {
   DCHECK(!shutdown_needed_);
 }
 
 DownloadItemImpl* DownloadManagerImpl::CreateActiveItem(
     uint32_t id,
     const DownloadCreateInfo& info) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!base::ContainsKey(downloads_, id));
   net::NetLogWithSource net_log =
       net::NetLogWithSource::Make(net_log_, net::NetLogSourceType::DOWNLOAD);
   DownloadItemImpl* download =
       item_factory_->CreateActiveItem(this, id, info, net_log);
   downloads_[id] = base::WrapUnique(download);
   downloads_by_guid_[download->GetGuid()] = download;
+
+  if (info.mime_type == kPDFMimeType && !info.has_user_gesture)
+    delegate_->RecordDriveByPDFDownload();
+
   return download;
 }
 
 void DownloadManagerImpl::GetNextId(const DownloadIdCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (delegate_) {
     delegate_->GetNextId(callback);
     return;
   }
   static uint32_t next_id = content::DownloadItem::kInvalidId + 1;
@@ skipping 531 matching lines @@
   if (delegate_)
     delegate_->OpenDownload(download);
 }
 
 void DownloadManagerImpl::ShowDownloadInShell(DownloadItemImpl* download) {
   if (delegate_)
     delegate_->ShowDownloadInShell(download);
 }
 
 }  // namespace content