mac: Turn on -Wunused-functions.

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 3197 matching lines @@
                 ],
               }]]
           }],
           ['clang==1', {
             'cflags': [
               '-Wheader-hygiene',
 
               # Don't die on dtoa code that uses a char as an array index.
               '-Wno-char-subscripts',
 
-              # Clang spots more unused functions.
+              # Clang spots more unused functions. TODO remove, crbug.com/315884
               '-Wno-unused-function',
 
               # Warns on switches on enums that cover all enum values but
               # also contain a default: branch. Chrome is full of that.
               '-Wno-covered-switch-default',
 
               # Warns when a const char[] is converted to bool.
               '-Wstring-conversion',
 
               # C++11-related flags:
@@ skipping 694 matching lines @@
                 # This warns on using ints as initializers for floats in
                 # initializer lists (e.g. |int a = f(); CGSize s = { a, a };|),
                 # which happens in several places in chrome code. Not sure if
                 # this is worth fixing.
                 '-Wno-c++11-narrowing',
 
                 # Don't die on dtoa code that uses a char as an array index.
                 # This is required solely for base/third_party/dmg_fp/dtoa.cc.
                 '-Wno-char-subscripts',
 
-                # Clang spots more unused functions.
-                '-Wno-unused-function',
+                # TODO(thakis): This used to be implied by -Wno-unused-function,
+                # which we no longer use. Check if it makes sense to remove
+                # this as well. http://crbug.com/316352
+                '-Wno-unneeded-internal-declaration',
 
                 # Warns on switches on enums that cover all enum values but
                 # also contain a default: branch. Chrome is full of that.
                 '-Wno-covered-switch-default',
 
                 # Warns when a const char[] is converted to bool.
                 '-Wstring-conversion',
 
                 # Clang considers the `register` keyword as deprecated, but e.g.
                 # code generated by flex (used in angle) contains that keyword.
@@ skipping 267 matching lines @@
           # section above).
           'CLANG_CXX_LANGUAGE_STANDARD': 'gnu++0x',
           # Warn if automatic synthesis is triggered with
           # the -Wobjc-missing-property-synthesis flag.
           'CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS': 'YES',
           'WARNING_CFLAGS': [
             '-Wheader-hygiene',
             # Don't die on dtoa code that uses a char as an array index.
             # This is required solely for base/third_party/dmg_fp/dtoa.cc.
             '-Wno-char-subscripts',
-            # Clang spots more unused functions.
+            # Clang spots more unused functions. TODO: remove, crbug.com/315884
             '-Wno-unused-function',
             # Match OS X clang C++11 warning settings.
             '-Wno-c++11-narrowing',
           ],
         },
         'target_conditions': [
           ['_toolset=="host"', {
             'xcode_settings': {
               'SDKROOT': 'macosx<(mac_sdk)',  # -isysroot
               'MACOSX_DEPLOYMENT_TARGET': '<(mac_deployment_target)',
@@ skipping 457 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',
   },
 }