Move creation and ownership of DownloadManager from the embedder to content. This matches all the o…

content/browser/download/download_manager_impl.cc

Index: content/browser/download/download_manager_impl.cc
===================================================================
--- content/browser/download/download_manager_impl.cc	(revision 140592)
+++ content/browser/download/download_manager_impl.cc	(working copy)
@@ -140,13 +140,6 @@
 
 namespace content {
 
-// static
-DownloadManager* DownloadManager::Create(
-    content::DownloadManagerDelegate* delegate,
-    net::NetLog* net_log) {
-  return new DownloadManagerImpl(delegate, net_log);
-}
-
 bool DownloadManager::EnsureNoPendingDownloadsForTesting() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   bool result = true;
@@ -159,14 +152,12 @@
 
 }  // namespace content
 
-DownloadManagerImpl::DownloadManagerImpl(
-    content::DownloadManagerDelegate* delegate,
-    net::NetLog* net_log)
-        : shutdown_needed_(false),
-          browser_context_(NULL),
-          file_manager_(NULL),
-          delegate_(delegate),
-          net_log_(net_log) {
+DownloadManagerImpl::DownloadManagerImpl(net::NetLog* net_log)
+    : shutdown_needed_(false),
+      browser_context_(NULL),
+      file_manager_(NULL),
+      delegate_(NULL),
+      net_log_(net_log) {
 }
 
 DownloadManagerImpl::~DownloadManagerImpl() {
@@ -185,6 +176,11 @@
   return delegate_->ShouldOpenFileBasedOnExtension(path);
 }
 
+void DownloadManagerImpl::SetDelegate(
+    content::DownloadManagerDelegate* delegate) {
+  delegate_ = delegate;
+}
+
 void DownloadManagerImpl::Shutdown() {
   VLOG(20) << __FUNCTION__ << "()"
            << " shutdown_needed_ = " << shutdown_needed_;
@@ -249,7 +245,8 @@
   DCHECK(save_page_downloads_.empty());
 
   file_manager_ = NULL;
-  delegate_->Shutdown();
+  if (delegate_)
+    delegate_->Shutdown();
 }
 
 void DownloadManagerImpl::GetTemporaryDownloads(