Remove trampoline between threads in SupportedImageTypeValidator.

chrome/browser/media_galleries/fileapi/supported_image_type_validator.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 "chrome/browser/media_galleries/fileapi/supported_image_type_validator.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/stl_util.h"
-#include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"
 #include "chrome/browser/image_decoder.h"
 #include "content/public/browser/browser_thread.h"
 
 using content::BrowserThread;
 
 namespace chrome {
 
 namespace {
 
@@ skipping 46 matching lines @@
     DCHECK(data_);
   }
 
   const std::string& data() {
     return *data_;
   }
 
   // ImageDecoder::Delegate methods.
   virtual void OnImageDecoded(const ImageDecoder* /*decoder*/,
                               const SkBitmap& /*decoded_image*/) OVERRIDE {
-    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
-                            base::Bind(callback_, base::PLATFORM_FILE_OK));
+    callback_.Run(base::PLATFORM_FILE_OK);
     delete this;
   }
 
   virtual void OnDecodeImageFailed(const ImageDecoder* /*decoder*/) OVERRIDE {
-    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
-                            base::Bind(callback_,
-                                       base::PLATFORM_FILE_ERROR_SECURITY));
+    callback_.Run(base::PLATFORM_FILE_ERROR_SECURITY);
     delete this;
   }
 
  private:
   scoped_ptr<std::string> data_;
   fileapi::CopyOrMoveFileValidator::ResultCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageDecoderDelegateAdapter);
 };
 
@@ skipping 40 matching lines @@
   if (!data.get()) {
     callback_.Run(base::PLATFORM_FILE_ERROR_SECURITY);
     return;
   }
 
   // |adapter| will delete itself after a completion message is received.
   ImageDecoderDelegateAdapter* adapter =
       new ImageDecoderDelegateAdapter(data.Pass(), callback_);
   decoder_ = new ImageDecoder(adapter, adapter->data(),
                               ImageDecoder::DEFAULT_CODEC);
-  base::SequencedWorkerPool* workerpool = BrowserThread::GetBlockingPool();
-  decoder_->Start(workerpool->GetSequencedTaskRunnerWithShutdownBehavior(
-        workerpool->GetSequenceToken(),
-        base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN));
+  decoder_->Start(content::BrowserThread::GetMessageLoopProxyForThread(
+      BrowserThread::IO));
 }
 
 }  // namespace chrome