mac: In component builds, put all chrome code in a nonbundle dylib. 25% faster incremental builds.

chrome/chrome_dll.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.
 {
   'conditions': [
     ['OS=="mac" or OS=="win"', {
       'targets': [
         {
           'target_name': 'chrome_dll',
           'type': 'none',
           'dependencies': [
             'chrome_main_dll',
           ],
           'conditions': [
+            ['OS=="mac" and component=="shared_library"', {
+              'type': 'shared_library',
+              'includes': [ 'chrome_dll_bundle.gypi' ],
+              'xcode_settings': {
+                'OTHER_LDFLAGS': [
+                  '-Wl,-reexport_library,<(PRODUCT_DIR)/libchrome_main_dll.dylib',
+                ],
+              },
+            }],  # OS=="mac"
             ['incremental_chrome_dll==1', {
               # Linking to a different directory and then hardlinking back
               # to OutDir is a workaround to avoid having the .ilk for
               # chrome.exe and chrome.dll conflicting. See crbug.com/92528
               # for more information. Done on the dll instead of the exe so
               # that people launching from VS don't need to modify
               # $(TargetPath) for the exe.
               'actions': [
                 {
                   'action_name': 'hardlink_to_output',
@@ skipping 137 matching lines @@
                     'winspool.drv',
                     'ws2_32.dll',
                     'wsock32.dll',
                   ],
                 },
                 'VCManifestTool': {
                   'AdditionalManifestFiles': '$(ProjectDir)\\app\\chrome.dll.manifest',
                 },
               },
             }],  # OS=="win"
+            ['OS=="mac" and component!="shared_library"', {
+              'includes': [ 'chrome_dll_bundle.gypi' ],
+            }],
+            ['OS=="mac" and component=="shared_library"', {
+              'xcode_settings': { 'OTHER_LDFLAGS': [ '-Wl,-ObjC' ], },
+            }],
             ['OS=="mac"', {
-             'includes': [ 'chrome_dll_bundle.gypi' ],
               'xcode_settings': {
                 # Define the order of symbols within the framework.  This
                 # sets -order_file.
                 'ORDER_FILE': 'app/framework.order',
               },
               'sources': [
                 'app/chrome_command_ids.h',
                 'app/chrome_dll_resource.h',
                 'app/chrome_main.cc',
                 'app/chrome_main_delegate.cc',
@@ skipping 44 matching lines @@
                   ],
                 }],
               ],  # conditions
             }],  # OS=="mac"
           ],  # conditions
         },  # target chrome_dll
       ],  # targets
     }],  # OS=="mac" or OS=="win"
   ],
 }