[Downloads] Always call DM::StartDownload() for explicit downloads.

content/browser/download/download_resource_handler.h

Index: content/browser/download/download_resource_handler.h
diff --git a/content/browser/download/download_resource_handler.h b/content/browser/download/download_resource_handler.h
index 2c1d4777b39cbbe92bd234f7f823ea2a40ee0961..fa5c2f36dc8d44087e05316ca09e41800a9d619e 100644
--- a/content/browser/download/download_resource_handler.h
+++ b/content/browser/download/download_resource_handler.h
@@ -97,11 +97,11 @@ class CONTENT_EXPORT DownloadResourceHandler
  private:
   virtual ~DownloadResourceHandler();
 
-  // Arrange for started_cb_ to be called on the UI thread with the
-  // below values, nulling out started_cb_.  Should only be called
-  // on the IO thread.
-  void CallStartedCB(DownloadItem* item,
-                     DownloadInterruptReason interrupt_reason);
+  void NotifyDownloadManagerOfSuccessfulResponseStart(
+      ResourceResponse* response);
+
+  void NotifyDownloadManagerOfFailedRequest(
+      DownloadInterruptReason interrupt_reason);
 
   uint32 download_id_;
   // This is read only on the IO thread, but may only
@@ -125,7 +125,7 @@ class CONTENT_EXPORT DownloadResourceHandler
   bool was_deferred_;
 
   // For DCHECKing
-  bool on_response_started_called_;
+  bool download_manager_notified_;
 
   static const int kReadBufSize = 32768;  // bytes
   static const int kThrottleTimeMs = 200;  // milliseconds