Added ability to set ChromeDownloadManagerDelegate for testing.

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index e698177a5c3e8b48a6b0f6e312e0b5a1077bd9ea..94ab40b1524d81a9cf53fd1966393938c0093843 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -1349,7 +1349,9 @@ void ProfileImpl::CreatePasswordStore() {
 
 DownloadManager* ProfileImpl::GetDownloadManager() {
   if (!created_download_manager_) {
-    download_manager_delegate_= new ChromeDownloadManagerDelegate(this);
+    // In case the delegate has already been set by SetDownloadManagerDelegate.
+    if (!download_manager_delegate_.get())
+      download_manager_delegate_= new ChromeDownloadManagerDelegate(this);
     scoped_refptr<DownloadManager> dlm(
         new DownloadManager(download_manager_delegate_,
                             g_browser_process->download_status_updater()));
@@ -1824,3 +1826,8 @@ SpellCheckProfile* ProfileImpl::GetSpellCheckProfile() {
     spellcheck_profile_.reset(new SpellCheckProfile());
   return spellcheck_profile_.get();
 }
+
+void ProfileImpl::SetDownloadManagerDelegate(
+    ChromeDownloadManagerDelegate* delegate) {
+  download_manager_delegate_ = delegate;
+}