Fix the HTML5 drag and drop demos on Linux and CrOS

ui/views/controls/textfield/textfield.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/controls/textfield/textfield.h"
 
 #include <string>
 
 #include "base/debug/trace_event.h"
 #include "grit/ui_strings.h"
@@ skipping 972 matching lines @@
       MenuRunner::HAS_MNEMONICS | MenuRunner::CONTEXT_MENU));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Textfield, DragController overrides:
 
 void Textfield::WriteDragDataForView(View* sender,
                                      const gfx::Point& press_pt,
                                      OSExchangeData* data) {
   const base::string16& selected_text(GetSelectedText());
-  data->SetString(selected_text);
   Label label(selected_text, GetFontList());
   const SkColor background = GetBackgroundColor();
   label.SetBackgroundColor(SkColorSetA(background, SK_AlphaTRANSPARENT));
   gfx::Size size(label.GetPreferredSize());
   gfx::NativeView native_view = GetWidget()->GetNativeView();
   gfx::Display display = gfx::Screen::GetScreenFor(native_view)->
       GetDisplayNearestWindow(native_view);
   size.SetToMin(gfx::Size(display.size().width(), height()));
   label.SetBoundsRect(gfx::Rect(size));
   scoped_ptr<gfx::Canvas> canvas(
       GetCanvasForDragImage(GetWidget(), label.size()));
   label.SetEnabledColor(GetTextColor());
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
   // Desktop Linux Aura does not yet support transparency in drag images.
   canvas->DrawColor(background);
 #endif
   label.Paint(canvas.get(), views::CullSet());
   const gfx::Vector2d kOffset(-15, 0);
   drag_utils::SetDragImageOnDataObject(*canvas, kOffset, data);
   if (controller_)
     controller_->OnWriteDragData(data);
+
+  // Set the string to |selected_text| if a string was not set by
+  // |controller_|.
+  if (!data->HasString())
+    data->SetString(selected_text);
 }
 
 int Textfield::GetDragOperationsForView(View* sender, const gfx::Point& p) {
   int drag_operations = ui::DragDropTypes::DRAG_COPY;
   if (!enabled() || text_input_type_ == ui::TEXT_INPUT_TYPE_PASSWORD ||
       !GetRenderText()->IsPointInSelection(p)) {
     drag_operations = ui::DragDropTypes::DRAG_NONE;
   } else if (sender == this && !read_only()) {
     drag_operations =
         ui::DragDropTypes::DRAG_MOVE | ui::DragDropTypes::DRAG_COPY;
@@ skipping 735 matching lines @@
       const size_t length = selection_clipboard_text.length();
       range = gfx::Range(range.start() + length, range.end() + length);
     }
     model_->MoveCursorTo(gfx::SelectionModel(range, affinity));
     UpdateAfterChange(true, true);
     OnAfterUserAction();
   }
 }
 
 }  // namespace views