Always use ENABLE_PLUGINS to indicate plugins support.

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 882 matching lines @@
           'ui_compositor_image_transport%': 1,
         }, {
           'ui_compositor_image_transport%': 0,
         }],
 
         # Turn precompiled headers on by default.
         ['OS=="win" and buildtype!="Official"', {
           'chromium_win_pch%': 1
         }],
 
+        # Whether PDF plugin is enabled.
+        ['OS=="android" or OS=="ios" or (embedded==1 and chromecast==0)', {
+          'enable_pdf%': 0,
+        }, {
+          'enable_pdf%': 1,
+        }],
+
         ['chromeos==1 or OS=="android" or OS=="ios" or desktop_linux==1', {
           'enable_plugin_installation%': 0,
         }, {
           'enable_plugin_installation%': 1,
         }],
 
         # Whether PPAPI is enabled.
         ['OS=="android" or OS=="ios" or (embedded==1 and chromecast==0)', {
           'enable_plugins%': 0,
         }, {
@@ skipping 284 matching lines @@
     'ubsan_vptr_blacklist%': '<(ubsan_vptr_blacklist)',
     'ubsan_vptr%': '<(ubsan_vptr)',
     'use_instrumented_libraries%': '<(use_instrumented_libraries)',
     'use_prebuilt_instrumented_libraries%': '<(use_prebuilt_instrumented_libraries)',
     'use_custom_libcxx%': '<(use_custom_libcxx)',
     'use_system_libcxx%': '<(use_system_libcxx)',
     'clang_type_profiler%': '<(clang_type_profiler)',
     'order_profiling%': '<(order_profiling)',
     'order_text_section%': '<(order_text_section)',
     'enable_extensions%': '<(enable_extensions)',
+    'enable_pdf%': '<(enable_pdf)',
     'enable_plugin_installation%': '<(enable_plugin_installation)',
     'enable_plugins%': '<(enable_plugins)',
     'enable_session_service%': '<(enable_session_service)',
     'enable_themes%': '<(enable_themes)',
     'enable_autofill_dialog%': '<(enable_autofill_dialog)',
     'enable_prod_wallet_service%': '<(enable_prod_wallet_service)',
     'enable_background%': '<(enable_background)',
     'linux_use_bundled_gold%': '<(linux_use_bundled_gold)',
     'linux_use_bundled_binutils%': '<(linux_use_bundled_binutils)',
     'linux_use_gold_flags%': '<(linux_use_gold_flags)',
@@ skipping 1762 matching lines @@
         'defines': [
           'ENABLE_EXTENSIONS=1',
         ],
       }],
       ['OS=="win" and branding=="Chrome"', {
         'defines': ['ENABLE_SWIFTSHADER'],
       }],
       ['enable_dart==1', {
         'defines': ['WEBKIT_USING_DART=1'],
       }],
+      ['enable_pdf==1', {
+        'defines': ['ENABLE_PDF=1'],
+      }],
       ['enable_plugin_installation==1', {
         'defines': ['ENABLE_PLUGIN_INSTALLATION=1'],
       }],
       ['enable_plugins==1', {
         'defines': ['ENABLE_PLUGINS=1'],
       }],
       ['enable_session_service==1', {
         'defines': ['ENABLE_SESSION_SERVICE=1'],
       }],
       ['enable_themes==1', {
@@ skipping 3314 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',
   },
 }