Integrate syzygy (optionally) into the chrome build process.

chrome/chrome_exe.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.
 
 {
   'target_defaults': {
     'variables': {
       'chrome_exe_target': 0,
     },
     'target_conditions': [
@@ skipping 397 matching lines @@
           ],
           'dependencies': [
             'packed_extra_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:flash_player',
           ],
         }],
         ['OS=="mac" or OS=="win"', {
-          'dependencies': [
-            # On Windows and Mac, make sure we've built chrome_dll, which
-            # contains all of the library code with Chromium functionality.
-            'chrome_dll',
+          'conditions': [
+            ['OS=="win" and optimize_with_syzygy==1', {
+              'dependencies': [
+                # When syzygy is enabled on Windows, make sure we've built the
+                # original chrome_dll, so that the optimize step can run. The
+                # optimization step will generate the final chrome_dll.
+                'original_chrome_dll',
+              ],
+            }, {
+              'dependencies': [
+                # On Windows and Mac, make sure we've built chrome_dll, which
+                # contains all of the library code with Chromium functionality.
+                'chrome_dll',
+              ],
+           }],
           ],
         }],
         ['OS=="win"', {
           'dependencies': [
             'chrome_version_resources',
             'installer_util',
             'installer_util_strings',
             '../base/base.gyp:base',
             '../breakpad/breakpad.gyp:breakpad_handler',
             '../breakpad/breakpad.gyp:breakpad_sender',
@@ skipping 58 matching lines @@
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',
             },
           },
         },
       ],
     }],
   ],
 }