x11: Use XI2.2 by default.

build/common.gypi

 # 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 363 matching lines @@
 
       # Enables support for background apps.
       'enable_background%': 1,
 
       # Enable the task manager by default.
       'enable_task_manager%': 1,
 
       # Enable FTP support by default.
       'disable_ftp_support%': 0,
 
-      # XInput2 multitouch support is disabled by default (use_xi2_mt=0).
-      # Setting to non-zero value enables XI2 MT. When XI2 MT is enabled,
+      # XInput2 multitouch support is enabled by default (use_xi2_mt=2).
+      # Setting to zero value disables XI2 MT. When XI2 MT is enabled,
       # the input value also defines the required XI2 minor minimum version.
       # For example, use_xi2_mt=2 means XI2.2 or above version is required.
-      'use_xi2_mt%': 0,
+      'use_xi2_mt%': 2,
 
       # Use of precompiled headers on Windows.
       #
       # This variable may be explicitly set to 1 (enabled) or 0
       # (disabled) in ~/.gyp/include.gypi or via the GYP command line.
       # This setting will override the default.
       #
       # See
       # http://code.google.com/p/chromium/wiki/WindowsPrecompiledHeaders
       # for details.
@@ skipping 4346 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }