Add PGO targets to Chrome.

build/internal/release_impl_official.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.
 {
   'includes': ['release_defaults.gypi'],
   'defines': ['OFFICIAL_BUILD'],
   'msvs_settings': {
     'VCCLCompilerTool': {
       'InlineFunctionExpansion': '2',
       'EnableIntrinsicFunctions': 'true',
@@ skipping 13 matching lines @@
       ],
     },
     'VCLinkerTool': {
       'AdditionalOptions': [
         '/time',
         # This may reduce memory fragmentation during linking.
         # The expected size is 40*1024*1024, which gives us about 10M of
         # headroom as of Dec 16, 2011.
         '/expectedoutputsize:41943040',
       ],
-      'LinkTimeCodeGeneration': '1',

[Sébastien Marchand, 2014/03/12 22:40:41]

This line shouldn't be removed because it prevent the targets (other than
chrome.dll and chrome_child.dll) to be linked with the /LTCG flag. However if I
don't remove this it overrides the values set in chrome_dll.gypi.

Even if I use <(ltcg_value) here it doesn't work, the last value set in
chrome_pgo.gypi gets used for the instrumented and the optimized version of the
DLL...

       # The /PROFILE flag causes the linker to add a "FIXUP" debug stream to
       # the generated PDB. According to MSDN documentation, this flag is only
       # available (or perhaps supported) in the Enterprise (team development)
       # version of Visual Studio. If this blocks your official build, simply
-      # comment out this line, then  re-run "gclient runhooks".
+      # comment out this line, then re-run "gclient runhooks".
       'Profile': 'true',
     },
   },
 }