Revert of clang/win: Stop passing -Qunused-arguments.

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 5612 matching lines @@
                 # PGO builds is likely very small.
                 'msvs_disabled_warnings': [
                   4702
                 ],
                 'msvs_settings': {
                   'VCCLCompilerTool': {
                     # 2, optimizeMaxSpeed, Maximize Speed (/O2)
                     'Optimization': '2',
                     # 1, favorSpeed - Favor fast code (/Ot)
                     'FavorSizeOrSpeed': '1',
+                    # This implies link time code generation.
+                    'WholeProgramOptimization': 'true',
                   },
                 },
-                # TODO(thakis): Remove clang==0 here, https://crbug.com/598772
-                'conditions': [
-                  ['clang==0', {
-                    'msvs_settings': {
-                      'VCCLCompilerTool': {
-                        # This implies link time code generation.
-                        'WholeProgramOptimization': 'true',
-                      },
-                    },
-                  }],
-                ],
               }],
             ],
           }],
           ['msvs_xtree_patched!=1', {
             # If xtree hasn't been patched, then we disable C4702. Otherwise,
             # it's enabled. This will generally only be true for system-level
             # installed Express users.
             'msvs_disabled_warnings': [
               4702, # unreachable code
             ],
@@ skipping 87 matching lines @@
 
           # TODO(brucedawson): http://crbug.com/593448 4334 is a 'suspicious
           # shift' warning and 4595 is an 'illegal inline operator new' warning
           # Both are new in VS 2015 Update 2 and can safely be deferred for now.
           4334, 4595,
         ],
         'msvs_settings': {
           'VCCLCompilerTool': {
             'AdditionalOptions': ['/MP'],
             'MinimalRebuild': 'false',
+            'BufferSecurityCheck': 'true',
             'EnableFunctionLevelLinking': 'true',
             'RuntimeTypeInfo': 'false',
             'WarningLevel': '4',
             'WarnAsError': 'true',
             'DebugInformationFormat': '3',
             # ExceptionHandling must match _HAS_EXCEPTIONS above.
             'ExceptionHandling': '0',
           },
           'VCLibrarianTool': {
             'AdditionalOptions': ['/ignore:4221'],
@@ skipping 52 matching lines @@
             }],
             ['_type=="executable" and ">(win_exe_compatibility_manifest)"!=""', {
               'VCManifestTool': {
                 'AdditionalManifestFiles': [
                   '>(win_exe_compatibility_manifest)',
                 ],
               },
             }],
           ],
           'conditions': [
-            ['clang==0', {
-              'VCCLCompilerTool': {
-                 # TODO(thakis): Enable this with clang too,
-                 # https://crbug.com/598767
-                 'BufferSecurityCheck': 'true',
-              },
-            }],
-
             # Building with Clang on Windows is a work in progress and very
             # experimental. See crbug.com/82385.
             # Keep this in sync with the similar blocks in build/config/compiler/BUILD.gn
             ['clang==1', {
               'VCCLCompilerTool': {
                 'AdditionalOptions': [
                   # Don't warn about unused function parameters.
                   # (This is also used on other platforms.)
                   '-Wno-unused-parameter',
                   # Don't warn about the "struct foo f = {0};" initialization
                   # pattern.
                   '-Wno-missing-field-initializers',
 
                   # Many files use intrinsics without including this header.
                   # TODO(hans): Fix those files, or move this to sub-GYPs.
                   '/FIIntrin.h',
 
                   # TODO(hans): Make this list shorter eventually, http://crbug.com/504657
+                  '-Qunused-arguments',  # http://crbug.com/504658
                   '-Wno-microsoft-enum-value',  # http://crbug.com/505296
                   '-Wno-unknown-pragmas',  # http://crbug.com/505314
                   '-Wno-microsoft-cast',  # http://crbug.com/550065
                 ],
               },
             }],
             ['clang==1 and clang_use_chrome_plugins==1', {
               'VCCLCompilerTool': {
                 'AdditionalOptions': [
                   '<@(clang_chrome_plugins_flags)',
@@ skipping 530 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',
   },
 }