Add more FS types and introduce type field into IsolatedContext

webkit/fileapi/file_system_context.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 "webkit/fileapi/file_system_context.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/stl_util.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 111 matching lines @@
       return sandbox_provider_.get();
     case kFileSystemTypeExternal:
       return external_provider_.get();
     case kFileSystemTypeIsolated:
       return isolated_provider_.get();
     default:
       if (provider_map_.find(type) != provider_map_.end())
         return provider_map_.find(type)->second;
       // Fall through.
     case kFileSystemTypeUnknown:
+    case kFileSystemTypeDragged:
       NOTREACHED();
       return NULL;
   }
 }
 
 SandboxMountPointProvider*
 FileSystemContext::sandbox_provider() const {
   return sandbox_provider_.get();
 }
 
@@ skipping 61 matching lines @@
   if (!io_task_runner_->RunsTasksOnCurrentThread() &&
       io_task_runner_->DeleteSoon(FROM_HERE, this)) {
     return;
   }
   STLDeleteContainerPairSecondPointers(provider_map_.begin(),
                                        provider_map_.end());
   delete this;
 }
 
 }  // namespace fileapi