Revert of Remove calls to MessageLoop::current() in content.

content/browser/download/drag_download_file.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/download/drag_download_file.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/single_thread_task_runner.h"
-#include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_save_info.h"
 #include "content/public/browser/download_url_parameters.h"
 
 namespace content {
 
 namespace {
 
 typedef base::Callback<void(bool)> OnCompleted;
 
 }  // namespace
 
 // On windows, DragDownloadFile runs on a thread other than the UI thread.
 // DownloadItem and DownloadManager may not be accessed on any thread other than
 // the UI thread. DragDownloadFile may run on either the "drag" thread or the UI
 // thread depending on the platform, but DragDownloadFileUI strictly always runs
 // on the UI thread. On platforms where DragDownloadFile runs on the UI thread,
 // none of the PostTasks are necessary, but it simplifies the code to do them
 // anyway.
 class DragDownloadFile::DragDownloadFileUI : public DownloadItem::Observer {
  public:
-  DragDownloadFileUI(
-      const GURL& url,
-      const Referrer& referrer,
-      const std::string& referrer_encoding,
-      WebContents* web_contents,
-      scoped_refptr<base::SingleThreadTaskRunner> on_completed_task_runner,
-      const OnCompleted& on_completed)
-      : on_completed_task_runner_(on_completed_task_runner),
+  DragDownloadFileUI(const GURL& url,
+                     const Referrer& referrer,
+                     const std::string& referrer_encoding,
+                     WebContents* web_contents,
+                     base::MessageLoop* on_completed_loop,
+                     const OnCompleted& on_completed)
+      : on_completed_loop_(on_completed_loop),
         on_completed_(on_completed),
         url_(url),
         referrer_(referrer),
         referrer_encoding_(referrer_encoding),
         web_contents_(web_contents),
         download_item_(NULL),
         weak_ptr_factory_(this) {
-    DCHECK(on_completed_task_runner_);
+    DCHECK(on_completed_loop_);
     DCHECK(!on_completed_.is_null());
     DCHECK(web_contents_);
     // May be called on any thread.
     // Do not call weak_ptr_factory_.GetWeakPtr() outside the UI thread.
   }
 
   void InitiateDownload(base::File file,
                         const base::FilePath& file_path) {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
     DownloadManager* download_manager =
@@ skipping 30 matching lines @@
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
     if (download_item_)
       download_item_->RemoveObserver(this);
   }
 
   void OnDownloadStarted(DownloadItem* item,
                          DownloadInterruptReason interrupt_reason) {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
     if (!item || item->GetState() != DownloadItem::IN_PROGRESS) {
       DCHECK(!item || item->GetLastReason() != DOWNLOAD_INTERRUPT_REASON_NONE);
-      on_completed_task_runner_->PostTask(FROM_HERE,
-                                          base::Bind(on_completed_, false));
+      on_completed_loop_->task_runner()->PostTask(
+          FROM_HERE, base::Bind(on_completed_, false));
       return;
     }
     DCHECK_EQ(DOWNLOAD_INTERRUPT_REASON_NONE, interrupt_reason);
     download_item_ = item;
     download_item_->AddObserver(this);
   }
 
   // DownloadItem::Observer:
   void OnDownloadUpdated(DownloadItem* item) override {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
     DCHECK_EQ(download_item_, item);
     DownloadItem::DownloadState state = download_item_->GetState();
     if (state == DownloadItem::COMPLETE ||
         state == DownloadItem::CANCELLED ||
         state == DownloadItem::INTERRUPTED) {
       if (!on_completed_.is_null()) {
-        on_completed_task_runner_->PostTask(
+        on_completed_loop_->task_runner()->PostTask(
             FROM_HERE,
             base::Bind(on_completed_, state == DownloadItem::COMPLETE));
         on_completed_.Reset();
       }
       download_item_->RemoveObserver(this);
       download_item_ = NULL;
     }
     // Ignore other states.
   }
 
   void OnDownloadDestroyed(DownloadItem* item) override {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
     DCHECK_EQ(download_item_, item);
     if (!on_completed_.is_null()) {
       const bool is_complete =
           download_item_->GetState() == DownloadItem::COMPLETE;
-      on_completed_task_runner_->PostTask(
+      on_completed_loop_->task_runner()->PostTask(
           FROM_HERE, base::Bind(on_completed_, is_complete));
       on_completed_.Reset();
     }
     download_item_->RemoveObserver(this);
     download_item_ = NULL;
   }
 
-  scoped_refptr<base::SingleThreadTaskRunner> const on_completed_task_runner_;
+  base::MessageLoop* on_completed_loop_;
   OnCompleted on_completed_;
   GURL url_;
   Referrer referrer_;
   std::string referrer_encoding_;
   WebContents* web_contents_;
   DownloadItem* download_item_;
 
   // Only used in the callback from DownloadManager::DownloadUrl().
   base::WeakPtrFactory<DragDownloadFileUI> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DragDownloadFileUI);
 };
 
 DragDownloadFile::DragDownloadFile(const base::FilePath& file_path,
                                    base::File file,
                                    const GURL& url,
                                    const Referrer& referrer,
                                    const std::string& referrer_encoding,
                                    WebContents* web_contents)
     : file_path_(file_path),
       file_(std::move(file)),
-      drag_task_runner_(base::ThreadTaskRunnerHandle::Get()),
+      drag_message_loop_(base::MessageLoop::current()),
       state_(INITIALIZED),
       drag_ui_(NULL),
       weak_ptr_factory_(this) {
   drag_ui_ = new DragDownloadFileUI(
-      url, referrer, referrer_encoding, web_contents, drag_task_runner_,
+      url,
+      referrer,
+      referrer_encoding,
+      web_contents,
+      drag_message_loop_,
       base::Bind(&DragDownloadFile::DownloadCompleted,
                  weak_ptr_factory_.GetWeakPtr()));
   DCHECK(!file_path_.empty());
 }
 
 DragDownloadFile::~DragDownloadFile() {
   CheckThread();
 
   // This is the only place that drag_ui_ can be deleted from. Post a message to
   // the UI thread so that it calls RemoveObserver on the right thread, and so
@@ skipping 47 matching lines @@
 
   // Release the observer since we do not need it any more.
   observer_ = NULL;
 
   if (nested_loop_.running())
     nested_loop_.Quit();
 }
 
 void DragDownloadFile::CheckThread() {
 #if defined(OS_WIN)
-  DCHECK(drag_task_runner_->BelongsToCurrentThread());
+  DCHECK(drag_message_loop_ == base::MessageLoop::current());
 #else
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 #endif
 }
 
 }  // namespace content