Compute pageScaleFactor on page so that fixed layout page fits width of window.

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 24 matching lines @@
 
           # Whether or not we are building the Ash shell.
           'use_ash%': 0,
 
           # Use OpenSSL instead of NSS. Under development: see http://crbug.com/62803
           'use_openssl%': 0,
 
           # Disable Virtual keyboard support by default.
           'use_virtual_keyboard%': 0,
 
+          # Disable viewport meta tag by default.
+          'enable_viewport%': 0,
+
           # Default setting for use_skia on mac platform.
           # This is typically overridden in use_skia_on_mac.gypi.
           'use_skia_on_mac%': 0,
         },
         # Copy conditionally-set variables out one scope.
         'chromeos%': '<(chromeos)',
         'chromeos_gtk%': '<(chromeos_gtk)',
         'use_aura%': '<(use_aura)',
         'use_ash%': '<(use_ash)',
         'use_openssl%': '<(use_openssl)',
         'use_virtual_keyboard%': '<(use_virtual_keyboard)',
+        'enable_viewport%': '<(enable_viewport)',
         'use_skia_on_mac%': '<(use_skia_on_mac)',
 
         # Compute the architecture that we're building on.
         'conditions': [
           [ 'OS=="win" or OS=="mac"', {
             'host_arch%': 'ia32',
           }, {
             # This handles the Unix platforms for which there is some support.
             # Anything else gets passed through, which probably won't work very
             # well; such hosts should pass an explicit target_arch to gyp.
@@ skipping 22 matching lines @@
 
       # Copy conditionally-set variables out one scope.
       'chromeos%': '<(chromeos)',
       'chromeos_gtk%': '<(chromeos_gtk)',
       'host_arch%': '<(host_arch)',
       'toolkit_views%': '<(toolkit_views)',
       'use_aura%': '<(use_aura)',
       'use_ash%': '<(use_ash)',
       'use_openssl%': '<(use_openssl)',
       'use_virtual_keyboard%': '<(use_virtual_keyboard)',
+      'enable_viewport%': '<(enable_viewport)',
       'use_skia_on_mac%': '<(use_skia_on_mac)',
 
       # We used to provide a variable for changing how libraries were built.
       # This variable remains until we can clean up all the users.
       # This needs to be one nested variables dict in so that dependent
       # gyp files can make use of it in their outer variables.  (Yikes!)
       # http://code.google.com/p/chromium/issues/detail?id=83308
       'library%': 'static_library',
 
       # Override branding to select the desired branding flavor.
@@ skipping 316 matching lines @@
     'toolkit_uses_gtk%': '<(toolkit_uses_gtk)',
     'use_skia%': '<(use_skia)',
     'use_x11%': '<(use_x11)',
     'use_gnome_keyring%': '<(use_gnome_keyring)',
     'linux_fpic%': '<(linux_fpic)',
     'enable_flapper_hacks%': '<(enable_flapper_hacks)',
     'enable_pepper_threading%': '<(enable_pepper_threading)',
     'chromeos%': '<(chromeos)',
     'chromeos_gtk%': '<(chromeos_gtk)',
     'use_virtual_keyboard%': '<(use_virtual_keyboard)',
+    'enable_viewport%': '<(enable_viewport)',
     'use_skia_on_mac%': '<(use_skia_on_mac)',
     'use_xi2_mt%':'<(use_xi2_mt)',
     'file_manager_extension%': '<(file_manager_extension)',
     'webui_task_manager%': '<(webui_task_manager)',
     'inside_chromium_build%': '<(inside_chromium_build)',
     'fastbuild%': '<(fastbuild)',
     'dcheck_always_on%': '<(dcheck_always_on)',
     'python_ver%': '<(python_ver)',
     'armv7%': '<(armv7)',
     'arm_neon%': '<(arm_neon)',
@@ skipping 668 matching lines @@
       }],
       ['proprietary_codecs==1', {
         'defines': ['USE_PROPRIETARY_CODECS'],
       }],
       ['enable_flapper_hacks==1', {
         'defines': ['ENABLE_FLAPPER_HACKS=1'],
       }],
       ['enable_pepper_threading==1', {
         'defines': ['ENABLE_PEPPER_THREADING'],
       }],
+      ['enable_viewport==1', {
+        'defines': ['ENABLE_VIEWPORT'],
+      }],
       ['configuration_policy==1', {
         'defines': ['ENABLE_CONFIGURATION_POLICY'],
       }],
       ['input_speech==1', {
         'defines': ['ENABLE_INPUT_SPEECH'],
       }],
       ['notifications==1', {
         'defines': ['ENABLE_NOTIFICATIONS'],
       }],
       ['fastbuild!=0', {
@@ skipping 1664 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',
   },
 }