Add support for /DEBUG:FASTLINK to gyp and gn files.

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 374 matching lines @@
       'use_system_libjpeg%': 0,
 
       # By default, component is set to static_library and it can be overriden
       # by the GYP command line or by ~/.gyp/include.gypi.
       'component%': 'static_library',
 
       # /analyze is off by default on Windows because it is very slow and noisy.
       # Enable with GYP_DEFINES=win_analyze=1
       'win_analyze%': 0,
 
+      # /debug:fastlink is off by default on Windows because it generates PDBs
+      # that are machine-local. But, great for local builds.
+      # Enable with GYP_DEFINES=win_fastlink=1
+      'win_fastlink%': 0,
+
       # Set to select the Title Case versions of strings in GRD files.
       'use_titlecase_in_grd%': 0,
 
       # Use translations provided by volunteers at launchpad.net.  This
       # currently only works on Linux.
       'use_third_party_translations%': 0,
 
       # Remoting compilation is enabled by default. Set to 0 to disable.
       'remoting%': 1,
 
@@ skipping 731 matching lines @@
     'tracing_like_official_build%': '<(tracing_like_official_build)',
     'arm_version%': '<(arm_version)',
     'arm_neon%': '<(arm_neon)',
     'arm_neon_optional%': '<(arm_neon_optional)',
     'sysroot%': '<(sysroot)',
     'pkg-config%': '<(pkg-config)',
     'chroot_cmd%': '<(chroot_cmd)',
     'system_libdir%': '<(system_libdir)',
     'component%': '<(component)',
     'win_analyze%': '<(win_analyze)',
+    'win_fastlink%': '<(win_fastlink)',
     'enable_resource_whitelist_generation%': '<(enable_resource_whitelist_generation)',
     'use_titlecase_in_grd%': '<(use_titlecase_in_grd)',
     'use_third_party_translations%': '<(use_third_party_translations)',
     'remoting%': '<(remoting)',
     'enable_one_click_signin%': '<(enable_one_click_signin)',
     'enable_pre_sync_backup%': '<(enable_pre_sync_backup)',
     'enable_media_router%': '<(enable_media_router)',
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
     'configuration_policy%': '<(configuration_policy)',
@@ skipping 2369 matching lines @@
           }, {
             'defines': [
               'MEMORY_TOOL_REPLACES_ALLOCATOR',
               'MEMORY_SANITIZER_INITIAL_SIZE',
               'DYNAMIC_ANNOTATIONS_ENABLED=1',
               'WTF_USE_DYNAMIC_ANNOTATIONS=1',
             ],
           }],
           ['OS=="win"', {
             'defines': ['NO_TCMALLOC'],
+            'conditions': [
+              ['win_fastlink==1', {
+                'msvs_settings': {
+                  'VCLinkerTool': {
+                    # /PROFILE is incompatible with /debug:fastlink
+                    'Profile': 'false',
+                    'AdditionalOptions': [
+                      # Tell VS 2015+ to create a PDB that references debug
+                      # information in .obj and .lib files instead of copying
+                      # it all.
+                      '/DEBUG:FASTLINK',
+                    ],
+                  },
+                },
+              }, {
+                # win_fastlink==0
+                'msvs_settings': {
+                  'VCLinkerTool': {
+                    # This corresponds to the /PROFILE flag which ensures the PDB
+                    # file contains FIXUP information (growing the PDB file by about
+                    # 5%) but does not otherwise alter the output binary. This
+                    # information is used by the Syzygy optimization tool when
+                    # decomposing the release image.
+                    'Profile': 'true',
+                  },
+                },
+              }],
+            ],
           }],
           # _FORTIFY_SOURCE isn't really supported by Clang now, see
           # http://llvm.org/bugs/show_bug.cgi?id=16821.
           # It seems to work fine with Ubuntu 12 headers though, so use it
           # in official builds.
           ['os_posix==1 and (asan!=1 and msan!=1 and tsan!=1 and lsan!=1 and ubsan!=1) and (OS!="linux" or clang!=1 or buildtype=="Official")', {
             'target_conditions': [
               ['chromium_code==1', {
                 # Non-chromium code is not guaranteed to compile cleanly
                 # with _FORTIFY_SOURCE. Also, fortified build may fail
@@ skipping 2700 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',
   },
 }