Use WebKit compositor in ui::Layer

build/common.gypi

 # Copyright (c) 2011 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 33 matching lines @@
           'use_openssl%': 0,
         },
         # Copy conditionally-set variables out one scope.
         'chromeos%': '<(chromeos)',
         'use_only_pure_views%': '<(use_only_pure_views)',
         'touchui%': '<(touchui)',
         'views_compositor%': '<(views_compositor)',
         'use_aura%': '<(use_aura)',
         'use_openssl%': '<(use_openssl)',
 
+        # WebKit compositor for ui
+        'use_webkit_compositor%': 0,
+
         # 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.
             'host_arch%':
               '<!(uname -m | sed -e "s/i.86/ia32/;s/x86_64/x64/;s/amd64/x64/;s/arm.*/arm/;s/i86pc/ia32/")',
@@ skipping 30 matching lines @@
       },
 
       # Copy conditionally-set variables out one scope.
       'chromeos%': '<(chromeos)',
       'touchui%': '<(touchui)',
       'use_virtual_keyboard%': '<(use_virtual_keyboard)',
       'host_arch%': '<(host_arch)',
       'toolkit_views%': '<(toolkit_views)',
       'use_only_pure_views%': '<(use_only_pure_views)',
       'views_compositor%': '<(views_compositor)',
+      'use_webkit_compositor%': '<(use_webkit_compositor)',
       'use_aura%': '<(use_aura)',
       'use_openssl%': '<(use_openssl)',
 
       # 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',
 
@@ skipping 212 matching lines @@
           'webui_task_manager%': 0,
         }],
 
         ['OS=="android"', {
           'proprietary_codecs%': 1,
           'enable_webrtc%': 0,
         }],
 
         # Use GPU accelerated cross process image transport by default
         # on TOUCH_UI and linux builds with the Aura window manager
-        ['views_compositor==1 and OS=="linux"', {
+        ['views_compositor==1 and OS=="linux" and use_webkit_compositor!=1', {
           'views_gpu_image_transport%': 1,
         }, {
           'views_gpu_image_transport%': 0,
         }],
       ],
     },
 
     # Copy conditionally-set variables out one scope.
     'branding%': '<(branding)',
     'buildtype%': '<(buildtype)',
     'target_arch%': '<(target_arch)',
     'host_arch%': '<(host_arch)',
     'library%': 'static_library',
     'toolkit_views%': '<(toolkit_views)',
     'use_only_pure_views%': '<(use_only_pure_views)',
     'views_compositor%': '<(views_compositor)',
     'views_gpu_image_transport%': '<(views_gpu_image_transport)',
+    'use_webkit_compositor%': '<(use_webkit_compositor)',
     'use_aura%': '<(use_aura)',
     'use_openssl%': '<(use_openssl)',
     'use_nss%': '<(use_nss)',
     'os_posix%': '<(os_posix)',
     'use_glib%': '<(use_glib)',
     'toolkit_uses_gtk%': '<(toolkit_uses_gtk)',
     'use_skia%': '<(use_skia)',
     'use_x11%': '<(use_x11)',
     'use_gnome_keyring%': '<(use_gnome_keyring)',
     'linux_fpic%': '<(linux_fpic)',
@@ skipping 583 matching lines @@
       }],
       ['use_only_pure_views==1', {
         'defines': ['USE_ONLY_PURE_VIEWS=1'],
       }],
       ['views_compositor==1', {
         'defines': ['VIEWS_COMPOSITOR=1'],
       }],
       ['views_gpu_image_transport==1', {
         'defines': ['UI_COMPOSITOR_IMAGE_TRANSPORT'],
       }],
+      ['use_webkit_compositor==1', {
+        'defines': ['USE_WEBKIT_COMPOSITOR=1'],
+      }],
       ['use_aura==1', {
         'defines': ['USE_AURA=1'],
       }],
       ['use_nss==1', {
         'defines': ['USE_NSS=1'],
       }],
       ['toolkit_uses_gtk==1', {
         'defines': ['TOOLKIT_USES_GTK=1'],
       }],
       ['chromeos==1', {
@@ skipping 1589 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',
   },
 }