Make snapshot_unittests depend on allocator.gyp:allocator when necessary

ui/snapshot/snapshot.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 48 matching lines @@
       ],
       'conditions': [
         ['use_aura==1', {
           'dependencies': [
             '../../base/base.gyp:test_support_base',
             '../aura/aura.gyp:aura_test_support',
             '../compositor/compositor.gyp:compositor',
             '../compositor/compositor.gyp:compositor_test_support',
           ],
         }],
+        # See http://crbug.com/162998#c4 for why this is needed.
+        ['OS=="linux" and linux_use_tcmalloc==1', {
+          'dependencies': [
+            '../../base/allocator/allocator.gyp:allocator',
+          ],
+        }],
       ],
     },
   ],
   'conditions': [
     ['OS=="win"', {
       'targets': [
         {
           'target_name': 'snapshot_test_support',
           'type': 'static_library',
           'sources': [
             'test/snapshot_desktop.h',
             'test/snapshot_desktop_win.cc',
           ],
           'dependencies': [
             'snapshot',
           ],
           'include_dirs': [
             '../..',
           ],
         },
       ],
     }],
   ],
 }