Add the pdf plugin's source in src\pdf.

chrome/chrome_exe.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.
 
 {
   'targets': [
     {
       'target_name': 'chrome',
       'type': 'none',
       'dependencies': [ 'chrome_initial', ],
@@ skipping 350 matching lines @@
               # framework's, and the ticket will reference this Info.plist to
               # determine the tag of the installed product.  Use --scm=1 to
               # include SCM information.  The --pdf flag controls whether
               # to insert PDF as a supported type identifier that can be
               # opened.
               'postbuild_name': 'Tweak Info.plist',
               'action': ['<(tweak_info_plist_path)',
                          '--breakpad=0',
                          '--keystone=<(mac_keystone)',
                          '--scm=1',
-                         '--pdf=<(internal_pdf)',
+                         '--pdf=1',
                          '--bundle_id=<(mac_bundle_id)'],
             },
             {
               'postbuild_name': 'Clean up old versions',
               'action': [
                 'tools/build/mac/clean_up_old_versions',
                 '<(version_full)'
               ],
             },
             {
@@ skipping 41 matching lines @@
         }, {  # OS != "mac"
           'conditions': [
             # TODO:  add a:
             #   'product_name': 'chromium'
             # whenever we convert the rest of the infrastructure
             # (buildbots etc.) to understand the branding gyp define.
             # NOTE: chrome/app/theme/chromium/BRANDING and
             # chrome/app/theme/google_chrome/BRANDING have the short name
             # "chrome" etc.; should we try to extract from there instead?
 
-            # On Mac, this is done in chrome_dll.gypi.
-            ['internal_pdf', {
+            # CrOS does this in a separate build step.
+            ['OS=="linux" and chromeos==0 and linux_dump_symbols==1', {
               'dependencies': [
-                '../pdf/pdf.gyp:pdf',
+                '../pdf/pdf.gyp:pdf_linux_symbols',
               ],
-              'conditions': [
-                # CrOS does this in a separate build step.
-                ['OS=="linux" and chromeos==0 and linux_dump_symbols==1', {
-                  'dependencies': [
-                    '../pdf/pdf.gyp:pdf_linux_symbols',
-                  ],
-                }], # OS=="linux" and chromeos==0 and linux_dump_symbols==1
-              ],
-            }], # internal_pdf
+            }], # OS=="linux" and chromeos==0 and linux_dump_symbols==1
           ],
           'dependencies': [
             '../components/components.gyp:startup_metric_utils',
+            # On Mac, this is done in chrome_dll.gypi.
+            '../pdf/pdf.gyp:pdf',
             'chrome_resources.gyp:packed_extra_resources',
             'chrome_resources.gyp:packed_resources',
             # Copy Flash Player files to PRODUCT_DIR if applicable. Let the .gyp
             # file decide what to do on a per-OS basis; on Mac, internal plugins
             # go inside the framework, so this dependency is in chrome_dll.gypi.
             '../third_party/adobe/flash/flash_player.gyp:flapper_binaries',
             # Copy CDM files to PRODUCT_DIR if applicable. Let the .gyp
             # file decide what to do on a per-OS basis; on Mac, internal plugins
             # go inside the framework, so this dependency is in chrome_dll.gypi.
             '../third_party/widevine/cdm/widevine_cdm.gyp:widevinecdmadapter',
@@ skipping 237 matching lines @@
               'dependencies': [
                 'chrome_nacl_win64',
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }