Remove {linux|android}_use_tcmalloc and switch to use_allocator in Chromium.

ipc/BUILD.gn

 # 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.
 
 component("ipc") {
   sources = [
     "file_descriptor_set_posix.cc",
     "file_descriptor_set_posix.h",
     "ipc_channel.cc",
     "ipc_channel.h",
@@ skipping 96 matching lines @@
       sources -= [ "unix_domain_socket_util_unittest.cc" ]
     }
 
     # TODO(brettw) hook up Android testing.
     #if (is_android && gtest_target_type == "shared_library") {
     #  deps += "/testing/android/native_test.gyp:native_testNative_code"
     #}
 
     # TODO(brettw) hook up tcmalloc to this target.
     #if (is_posix && !is_mac && !is_android) {
-    #  # TODO(dmikurube): Kill linux_use_tcmalloc. http://crbug.com/345554
-    #  if ((use_allocator!="none" && use_allocator!="see_use_tcmalloc") || (use_allocator=="see_use_tcmalloc" && linux_use_tcmalloc)) {
+    #  if (use_allocator!="none") {
     #    deps += "/base/allocator"
     #  }
     #}
 
     deps = [
       ":ipc",
       ":test_support_ipc",
       "//base",
       "//base:i18n",
       "//base/test:run_all_unittests",
       "//base/test:test_support",
       "//testing/gtest",
     ]
   }
 
   test("ipc_perftests") {
     sources = [
       "ipc_perftests.cc",
       "ipc_test_base.cc",
       "ipc_test_base.h",
     ]
 
     # TODO(brettw) hook up Android testing.
     #if (is_android && gtest_target_type == "shared_library") {
     #  deps += "/testing/android/native_test.gyp:native_testNative_code"
     #}
 
     # TODO(brettw) hook up tcmalloc to this target.
     #if (is_posix && !is_mac && !is_android) {
-    #  # TODO(dmikurube): Kill linux_use_tcmalloc. http://crbug.com/345554
-    #  if ((use_allocator!="none" && use_allocator!="see_use_tcmalloc") || (use_allocator=="see_use_tcmalloc" && linux_use_tcmalloc)) {
+    #  if (use_allocator!="none") {
     #    deps += "//base/allocator"
     #  }
     #}
 
     deps = [
       ":ipc",
       ":test_support_ipc",
       "//base",
       "//base:i18n",
       "//base/test:test_support",
@@ skipping 10 matching lines @@
     "ipc_test_sink.cc",
     "ipc_test_sink.h",
   ]
   deps = [
     ":ipc",
     "//base",
     "//testing/gtest",
   ]
 }