Update build settings for coverage on Windows.

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 1754 matching lines @@
               ['_type!="static_library"', {
                 'xcode_settings': { 'OTHER_LDFLAGS': [ '-lgcov' ] },
               }],
             ],
           }],
           ['OS=="linux" or OS=="android"', {
             'cflags': [ '-ftest-coverage',
                         '-fprofile-arcs' ],
             'link_settings': { 'libraries': [ '-lgcov' ] },
           }],
-          # Finally, for Windows, we simply turn on profiling.
           ['OS=="win"', {
+            'variables': {
+              # Disable incremental linking for all modules.
+              # 0: inherit, 1: disabled, 2: enabled.
+              'msvs_debug_link_incremental': '1',
+              'msvs_large_module_debug_link_mode': '1',
+            },
+            'defines': [
+              # Disable iterator debugging (huge speed boost without any
+              # change in coverage results).
+              '_HAS_ITERATOR_DEBUGGING=0',
+            ],
             'msvs_settings': {
               'VCLinkerTool': {
+                # Enable profile information (necessary for coverage
+                # instrumentation). This is incompatible with incremental
+                # linking.
                 'Profile': 'true',
               },
-              'VCCLCompilerTool': {
-                # /Z7, not /Zi, so coverage is happyb
-                'DebugInformationFormat': '1',
-                'AdditionalOptions': ['/Yd'],
-              }
             }
          }],  # OS==win
         ],  # conditions for coverage
       }],  # coverage!=0
       ['OS=="win"', {
         'defines': [
           '__STD_C',
           '_CRT_SECURE_NO_DEPRECATE',
           '_SCL_SECURE_NO_DEPRECATE',
           # This define is required to pull in the new Win8 interfaces from
@@ skipping 156 matching lines @@
               },
             },
             'conditions': [
               ['buildtype=="Official"', {
                 'msvs_settings': {
                   'VCCLCompilerTool': { 'WarnAsError': 'false' },
                 }
               }],
             ],
           }],
-          # TODO(darin): Unfortunately, some third_party code depends on base/
+          # TODO(darin): Unfortunately, some third_party code depends on base.
           [ 'OS=="win" and component=="shared_library"', {
             'msvs_disabled_warnings': [
               4251,  # class 'std::xx' needs to have dll-interface.
             ],
           }],
           [ 'OS=="mac" or OS=="ios"', {
             'xcode_settings': {
               'WARNING_CFLAGS!': ['-Wall', '-Wextra'],
             },
             'conditions': [
@@ skipping 1878 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',
   },
 }