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

content/browser/download/download_item_impl.h

Index: content/browser/download/download_item_impl.h
diff --git a/content/browser/download/download_item_impl.h b/content/browser/download/download_item_impl.h
index f8f6cbc37278085ff04d2db8832c78692ec9c8af..a5d6db9e89da8dae697eb9d5d00f733c270c4523 100644
--- a/content/browser/download/download_item_impl.h
+++ b/content/browser/download/download_item_impl.h
@@ -163,18 +163,18 @@ class CONTENT_EXPORT DownloadItemImpl
   // INTERRUPTED state.
   virtual ResumeMode GetResumeMode() const;
 
-  // Notify the download item that new origin information is available due to a
-  // resumption request receiving a response.
-  virtual void MergeOriginInfoOnResume(
-      const DownloadCreateInfo& new_create_info);
-
   // State transition operations on regular downloads --------------------------
 
   // Start the download.
   // |download_file| is the associated file on the storage medium.
   // |req_handle| is the new request handle associated with the download.
+  // |new_create_info| is a DownloadCreateInfo containing the new response
+  // parameters. It may be different from the DownloadCreateInfo used to create
+  // the DownloadItem if Start() is being called in response for a download
+  // resumption request.
   virtual void Start(scoped_ptr<DownloadFile> download_file,
-                     scoped_ptr<DownloadRequestHandleInterface> req_handle);
+                     scoped_ptr<DownloadRequestHandleInterface> req_handle,
+                     const DownloadCreateInfo& new_create_info);
 
   // Needed because of intertwining with DownloadManagerImpl -------------------
 
@@ -339,10 +339,6 @@ class CONTENT_EXPORT DownloadItemImpl
   // is completed.
   void Completed();
 
-  // Callback invoked when the URLRequest for a download resumption has started.
-  void OnResumeRequestStarted(DownloadItem* item,
-                              DownloadInterruptReason interrupt_reason);
-
   // Helper routines -----------------------------------------------------------
 
   // Indicate that an error has occurred on the download.
@@ -374,6 +370,11 @@ class CONTENT_EXPORT DownloadItemImpl
 
   void ResumeInterruptedDownload();
 
+  // Update origin information based on the response to a download resumption
+  // request. Should only be called if the resumption request was successful.
+  virtual void MergeOriginInfoOnResume(
+      const DownloadCreateInfo& new_create_info);
+
   static DownloadState InternalToExternalState(
       DownloadInternalState internal_state);
   static DownloadInternalState ExternalToInternalState(