Downloads: replace BrowserThread::FILE with task scheduler.

content/browser/download/docs/save-page-as.md

Index: content/browser/download/docs/save-page-as.md
diff --git a/content/browser/download/docs/save-page-as.md b/content/browser/download/docs/save-page-as.md
index 8b170ef6462d2e3b1eea49c9399e7e87110c1446..cb6f38a5cee87b5719f99e3eab816c03bd24353d 100644
--- a/content/browser/download/docs/save-page-as.md
+++ b/content/browser/download/docs/save-page-as.md
@@ -26,11 +26,11 @@ are described by their code comments or by their code structure).
     * UI-thread object
 
 * SaveFileManager class
-    * coordinates between FILE and UI threads
+    * coordinates between the download sequence and the UI thread
         * Gets requests from `SavePackage` and communicates results back to
           `SavePackage` on the UI thread.
         * Shephards data (received from the network OR from DOM) into
-          FILE thread - via `SaveFileManager::UpdateSaveProgress`
+          the download sequence - via `SaveFileManager::UpdateSaveProgress`
     * created and owned by `BrowserMainLoop`
       (ref-counted today, but it is unnecessary - see https://crbug.com/596953)
     * The global instance can be retrieved by the Get method.
@@ -38,11 +38,11 @@ are described by their code comments or by their code structure).
 * SaveFile class
     * tracks saving a single file
     * created and owned by `SaveFileManager`
-    * FILE-thread object
+    * download sequence object
 
 * SaveFileResourceHandler class
     * tracks network downloads + forwards their status into `SaveFileManager`
-      (onto FILE-thread)
+      (onto download sequence)
     * created by `ResourceDispatcherHostImpl::BeginSaveFile`
     * IO-thread object