Remove touch_drag_drop web preference. It was added in r184242 for tests to be

content/shell/common/webkit_test_helpers.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 "content/shell/common/webkit_test_helpers.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/utf_string_conversions.h"
@@ skipping 32 matching lines @@
   to->allow_running_insecure_content = from.allowRunningOfInsecureContent;
   to->css_shaders_enabled = from.cssCustomFilterEnabled;
   to->should_respect_image_orientation = from.shouldRespectImageOrientation;
   to->asynchronous_spell_checking_enabled =
       from.asynchronousSpellCheckingEnabled;
   to->allow_file_access_from_file_urls = from.allowFileAccessFromFileURLs;
   to->author_and_user_styles_enabled = from.authorAndUserStylesEnabled;
   to->javascript_can_open_windows_automatically =
       from.javaScriptCanOpenWindowsAutomatically;
   to->user_style_sheet_location = from.userStyleSheetLocation;
-  to->touch_drag_drop_enabled = from.touchDragDropEnabled;
 }
 
 // Applies settings that differ between layout tests and regular mode. Some
 // of the defaults are controlled via command line flags which are
 // automatically set for layout tests.
 void ApplyLayoutTestDefaultPreferences(WebPreferences* prefs) {
   CommandLine& command_line = *CommandLine::ForCurrentProcess();
   prefs->allow_universal_access_from_file_urls = true;
   prefs->dom_paste_enabled = true;
   prefs->javascript_can_access_clipboard = true;
@@ skipping 73 matching lines @@
           FILE_PATH_LITERAL("Source/WebKit/chromium/webkit/support")))) {
     // We're in a WebKit-only checkout.
     return webkit_path.Append(FILE_PATH_LITERAL("Source/WebKit/chromium"));
   } else {
     // We're in a Chromium checkout, and WebKit is in third_party/WebKit.
     return webkit_path.Append(FILE_PATH_LITERAL("../.."));
   }
 }
 
 }  // namespace content