Revert 215787 "Support synchronous mode in WebFileWriterImpl"

trunk/src/content/child/fileapi/webfilewriter_impl.cc

 // Copyright 2013 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/child/fileapi/webfilewriter_impl.h"
 
 #include "base/bind.h"
 #include "base/platform_file.h"
-#include "base/synchronization/waitable_event.h"
 #include "content/child/child_thread.h"
 #include "content/child/fileapi/file_system_dispatcher.h"
 #include "webkit/child/worker_task_runner.h"
 
 using webkit_glue::WorkerTaskRunner;
 
 namespace content {
 
 namespace {
 
 FileSystemDispatcher* GetFileSystemDispatcher() {
   return ChildThread::current() ?
       ChildThread::current()->file_system_dispatcher() : NULL;
 }
 
 }  // namespace
 
 typedef FileSystemDispatcher::StatusCallback StatusCallback;
 typedef FileSystemDispatcher::WriteCallback WriteCallback;
 
 // This instance may be created outside main thread but runs mainly
 // on main thread.
 class WebFileWriterImpl::WriterBridge
     : public base::RefCountedThreadSafe<WriterBridge> {
  public:
-  WriterBridge(WebFileWriterImpl::Type type)
+  WriterBridge()
       : request_id_(0),
-        thread_id_(WorkerTaskRunner::Instance()->CurrentWorkerId()),
-        written_bytes_(0) {
-    if (type == WebFileWriterImpl::TYPE_SYNC)
-      waitable_event_.reset(new base::WaitableEvent(false, false));
-  }
+        thread_id_(WorkerTaskRunner::Instance()->CurrentWorkerId()) {}
 
   void Truncate(const GURL& path, int64 offset,
                 const StatusCallback& status_callback) {
     status_callback_ = status_callback;
     if (!GetFileSystemDispatcher())
       return;
     ChildThread::current()->file_system_dispatcher()->Truncate(
         path, offset, &request_id_,
         base::Bind(&WriterBridge::DidFinish, this));
   }
@@ skipping 13 matching lines @@
 
   void Cancel(const StatusCallback& status_callback) {
     status_callback_ = status_callback;
     if (!GetFileSystemDispatcher())
       return;
     ChildThread::current()->file_system_dispatcher()->Cancel(
         request_id_,
         base::Bind(&WriterBridge::DidFinish, this));
   }
 
-  base::WaitableEvent* waitable_event() {
-    return waitable_event_.get();
-  }
-
-  void WaitAndRun() {
-    waitable_event_->Wait();
-    DCHECK(!results_closure_.is_null());
-    results_closure_.Run();
-    written_bytes_ = 0;
-  }
-
  private:
   friend class base::RefCountedThreadSafe<WriterBridge>;
   virtual ~WriterBridge() {}
 
   void DidWrite(int64 bytes, bool complete) {
-    written_bytes_ += bytes;
-    if (waitable_event_ && !complete)
-      return;
-    PostTaskToWorker(base::Bind(write_callback_, written_bytes_, complete));
+    PostTaskToWorker(base::Bind(write_callback_, bytes, complete));
   }
 
   void DidFinish(base::PlatformFileError status) {
     PostTaskToWorker(base::Bind(status_callback_, status));
   }
 
   void PostTaskToWorker(const base::Closure& closure) {
-    if (!thread_id_) {
-      DCHECK(!waitable_event_);
+    if (!thread_id_)
       closure.Run();
-      return;
-    }
-    if (waitable_event_) {
-      results_closure_ = closure;
-      waitable_event_->Signal();
-      return;
-    }
-    WorkerTaskRunner::Instance()->PostTask(thread_id_, closure);
-    written_bytes_ = 0;
+    else
+      WorkerTaskRunner::Instance()->PostTask(thread_id_, closure);
   }
 
   StatusCallback status_callback_;
   WriteCallback write_callback_;
   int request_id_;
   int thread_id_;
-  int written_bytes_;
-  scoped_ptr<base::WaitableEvent> waitable_event_;
-  base::Closure results_closure_;
 };
 
 WebFileWriterImpl::WebFileWriterImpl(
      const GURL& path, WebKit::WebFileWriterClient* client,
-     Type type,
      base::MessageLoopProxy* main_thread_loop)
   : WebFileWriterBase(path, client),
     main_thread_loop_(main_thread_loop),
-    bridge_(new WriterBridge(type)) {
+    bridge_(new WriterBridge) {
 }
 
 WebFileWriterImpl::~WebFileWriterImpl() {
 }
 
 void WebFileWriterImpl::DoTruncate(const GURL& path, int64 offset) {
   RunOnMainThread(base::Bind(&WriterBridge::Truncate, bridge_,
       path, offset,
       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
 }
 
 void WebFileWriterImpl::DoWrite(
     const GURL& path, const GURL& blob_url, int64 offset) {
   RunOnMainThread(base::Bind(&WriterBridge::Write, bridge_,
       path, blob_url, offset,
       base::Bind(&WebFileWriterImpl::DidWrite, AsWeakPtr()),
       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
 }
 
 void WebFileWriterImpl::DoCancel() {
   RunOnMainThread(base::Bind(&WriterBridge::Cancel, bridge_,
       base::Bind(&WebFileWriterImpl::DidFinish, AsWeakPtr())));
 }
 
 void WebFileWriterImpl::RunOnMainThread(const base::Closure& closure) {
-  if (main_thread_loop_->RunsTasksOnCurrentThread()) {
-    DCHECK(!bridge_->waitable_event());
+  if (main_thread_loop_->RunsTasksOnCurrentThread())
     closure.Run();
-    return;
-  }
-  main_thread_loop_->PostTask(FROM_HERE, closure);
-  if (bridge_->waitable_event())
-    bridge_->WaitAndRun();
+  else
+    main_thread_loop_->PostTask(FROM_HERE, closure);
 }
 
 }  // namespace content