linux: pass --gc-sections in link line

build/common.gypi

 # Copyright (c) 2009 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': {
     # .gyp files should set chromium_code to 1 if they build Chromium-specific
@@ skipping 596 matching lines @@
             'cflags': [
               '-O>(release_optimize)',
               # Don't emit the GCC version ident directives, they just end up
               # in the .comment section taking up binary size.
               '-fno-ident',
               # Put data and code in their own sections, so that unused symbols
               # can be removed at link time with --gc-sections.
               '-fdata-sections',
               '-ffunction-sections',
             ],
+            'ldflags': [
+              '-Wl,--gc-sections',
+            ],
           },
         },
         'variants': {
           'coverage': {
             'cflags': ['-fprofile-arcs', '-ftest-coverage'],
             'ldflags': ['-fprofile-arcs'],
           },
           'profile': {
             'cflags': ['-pg', '-g'],
             'ldflags': ['-pg'],
@@ skipping 345 matching lines @@
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: