Allow OSExchangeData::Provider to be overridden at run time.

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.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 "ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.h"
 
 #include <X11/Xatom.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 589 matching lines @@
     const XClientMessageEvent& event) {
   DVLOG(1) << "XdndDrop";
 
   unsigned long source_window = event.data.l[0];
 
   int drag_operation = ui::DragDropTypes::DRAG_NONE;
   if (target_window_) {
     aura::client::DragDropDelegate* delegate =
         aura::client::GetDragDropDelegate(target_window_);
     if (delegate) {
-      ui::OSExchangeData data(new ui::OSExchangeDataProviderAuraX11(
-          xwindow_, target_current_context_->fetched_targets()));
+      ui::OSExchangeData data(
+          base::MakeUnique<ui::OSExchangeDataProviderAuraX11>(
+              xwindow_, target_current_context_->fetched_targets()));
 
       ui::DropTargetEvent event(data,
                                 target_window_location_,
                                 target_window_root_location_,
                                 target_current_context_->GetDragOperation());
       if (target_current_context_->source_client()) {
         event.set_flags(target_current_context_->source_client()
                             ->current_modifier_state());
       } else {
         event.set_flags(XGetModifiers());
@@ skipping 352 matching lines @@
       target_window_->AddObserver(this);
     target_window_changed = true;
   }
   *delegate = NULL;
   if (!target_window_)
     return;
   *delegate = aura::client::GetDragDropDelegate(target_window_);
   if (!*delegate)
     return;
 
-  data->reset(new OSExchangeData(new ui::OSExchangeDataProviderAuraX11(
-      xwindow_, target_current_context_->fetched_targets())));
+  data->reset(new OSExchangeData(
+      base::MakeUnique<ui::OSExchangeDataProviderAuraX11>(
+          xwindow_, target_current_context_->fetched_targets())));
   gfx::Point location = root_location;
   aura::Window::ConvertPointToTarget(root_window_, target_window_, &location);
 
   target_window_location_ = location;
   target_window_root_location_ = root_location;
 
   int drag_op = target_current_context_->GetDragOperation();
   // KDE-based file browsers such as Dolphin change the drag operation depending
   // on whether alt/ctrl/shift was pressed. However once Chromium gets control
   // over the X11 events, the source application does no longer receive X11
@@ skipping 232 matching lines @@
     for (int x = 0; x < in_bitmap->width(); ++x) {
       if (SkColorGetA(in_row[x]) > kMinAlpha)
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace views