WebUI TaskManager: Turn it off by default on Win/Mac/Linux

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 118 matching lines @@
       # Set to 1 to enable fast builds. It disables debug info for fastest
       # compilation.
       'fastbuild%': 0,
 
       # Set to 1 to enable dcheck in release without having to use the flag.
       'dcheck_always_on%': 0,
 
       # Disable file manager component extension by default.
       'file_manager_extension%': 0,
 
-      # Enable WebUI TaskManager by default.
-      'webui_task_manager%': 1,
+      # Disable WebUI TaskManager by default.
+      'webui_task_manager%': 0,
 
       # Python version.
       'python_ver%': '2.6',
 
       # Set ARM-v7 compilation flags
       'armv7%': 0,
 
       # Set Neon compilation flags (only meaningful if armv7==1).
       'arm_neon%': 1,
 
@@ skipping 201 matching lines @@
           'file_manager_extension%': 1,
         }, {
           'file_manager_extension%': 0,
         }],
 
         # ... except on Windows even with Aura.
         ['use_aura==1 and OS=="win"', {
           'file_manager_extension%': 0,
         }],
 
-        # Enable WebUI TaskManager always on Chrome OS or Aura.
+        # Enable WebUI TaskManager on Chrome OS or Aura.
         ['chromeos==1 or use_aura==1', {
           'webui_task_manager%': 1,
         }],
 
         ['OS=="android"', {
           'proprietary_codecs%': 1,
           'enable_webrtc%': 0,
         }],
 
         # Use GPU accelerated cross process image transport by default
@@ skipping 2438 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',
   },
 }