[Android] Build android tools as PIE and add a wrapper for ICS

tools/android/purge_ashmem/purge_ashmem.gyp

 # Copyright 2013 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.
 
 {
   'targets': [
     {
       'target_name': 'purge_ashmem',
       'type': 'executable',
       'dependencies': [
         '../../../third_party/ashmem/ashmem.gyp:ashmem',
       ],
       'include_dirs': [
         '../../../',
       ],
-      'conditions': [
-        # Warning: A PIE tool cannot run on ICS 4.0.4, so only
-        #          build it as position-independent when ASAN
-        #          is activated. See b/6587214 for details.
-        [ 'asan==1', {
-          'cflags': [
-            '-fPIE',
-          ],
-          'ldflags': [
-            '-pie',
-          ],
-        }],
-      ],
       'sources': [
         'purge_ashmem.c',
       ],
     },
   ],
 }