Two changes related to the asan=1 mode:

build/common.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.
 
 # 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 179 matching lines @@
 
       # Notifications are compiled in by default. Set to 0 to disable.
       'notifications%' : 1,
 
       # If this is set, the clang plugins used on the buildbot will be used.
       # Run tools/clang/scripts/update.sh to make sure they are compiled.
       # This causes 'clang_chrome_plugins_flags' to be set.
       # Has no effect if 'clang' is not set as well.
       'clang_use_chrome_plugins%': 0,
 
-      # Enable building with ASAN (Clang's -fasan option).
-      # -fasan only works with clang, but asan=1 implies clang=1
+      # Enable building with ASAN (Clang's -faddress-sanitizer option).
+      # -faddress-sanitizer only works with clang, but asan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/addresssanitizer
       'asan%': 0,
 
       # Set to 1 compile with -fPIC cflag on linux. This is a must for shared
       # libraries on linux x86-64 and arm, plus ASLR.
       'linux_fpic%': 1,
 
       # Enable navigator.registerProtocolHandler and supporting UI.
       'enable_register_protocol_handler%': 1,
 
@@ skipping 1704 matching lines @@
           }],
           ['clang==1 and clang_load!="" and clang_add_plugin!=""', {
             'cflags': [
               '-Xclang', '-load', '-Xclang', '<(clang_load)',
               '-Xclang', '-add-plugin', '-Xclang', '<(clang_add_plugin)',
             ],
           }],
           ['asan==1', {
             # Only in the linux section for now, since ASAN doesn't
             # work on Mac yet.
+            # TODO(glider): -fasan is deprecated. Remove it when we stop using
+            # it.
             'cflags': [
               '-fasan',
+              '-faddress-sanitizer',
               '-w',
+              '-DADDRESS_SANITIZER',
             ],
             'ldflags': [
               '-fasan',
+              '-faddress-sanitizer',
             ],
           }],
           ['no_strict_aliasing==1', {
             'cflags': [
               '-fno-strict-aliasing',
             ],
           }],
           ['linux_breakpad==1', {
             'cflags': [ '-g' ],
             'defines': ['USE_LINUX_BREAKPAD'],
@@ skipping 680 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',
   },
 }