Add test for multithreaded ActiveVerifier behavior.

base/BUILD.gn

 # Copyright (c) 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 1575 matching lines @@
     ]
     libs = [
       "cfgmgr32.lib",
       "shell32.lib",
     ]
     deps = [
       "//build/config/sanitizers:deps",
     ]
   }
 
+  shared_library("scoped_handle_test_dll") {
+    sources = [
+      "win/scoped_handle_test_dll.cc",
+    ]
+    deps = [
+      ":base",

[Nico, 2016/03/11 23:26:58]

...you really want to link base into your test dll?

[Will Harris, 2016/03/12 00:00:01]

yes, because I need to test behavior of base's active verifier from an exe and a
dll loaded within the exe.

+    ]
+  }
+
   if (target_cpu == "x64") {
     # Must be a shared library so that it can be unloaded during testing.
     shared_library("base_profiler_test_support_library") {
       sources = [
         "profiler/test_support_library.cc",
       ]
       deps = [
         "//build/config/sanitizers:deps",
       ]
     }
@@ skipping 343 matching lines @@
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
     set_sources_assignment_filter([])
     sources += [
       "debug/proc_maps_linux_unittest.cc",
       "trace_event/trace_event_android_unittest.cc",
     ]
     set_sources_assignment_filter(sources_assignment_filter)
   }
 
-  if (is_win && target_cpu == "x64") {
-    sources += [ "profiler/win32_stack_frame_unwinder_unittest.cc" ]
-    deps += [ ":base_profiler_test_support_library" ]
+  if (is_win) {
+    deps += [ "//base:scoped_handle_test_dll" ]

[Nico, 2016/03/11 23:26:58]

is this a dll loaded by tests? does it need to be in a data section so that the
test can run on swarming?

[Will Harris, 2016/03/12 00:00:01]

once I changed this to loadable_library then isolate picked it up.

+    if (target_cpu == "x64") {
+      sources += [ "profiler/win32_stack_frame_unwinder_unittest.cc" ]
+      deps += [ ":base_profiler_test_support_library" ]
+    }
   }
 
   if (use_experimental_allocator_shim) {
     sources += [ "allocator/allocator_shim_unittest.cc" ]
   }
 
   # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   # Symbols for crashes when running tests on swarming.
@@ skipping 196 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }