Stack sampling profiler: handle unloaded and unloading modules

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.
 
 import("//build/config/compiler/compiler.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
@@ skipping 1172 matching lines @@
       "/SUBSYSTEM:WINDOWS",
     ]
     libs = [
       "cfgmgr32.lib",
       "shell32.lib",
     ]
     deps = [
       "//build/config/sanitizers:deps",
     ]
   }
+
+  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",
+      ]
+    }
+  }
 }
 
 # TODO(GYP): Delete this after we've converted everything to GN.
 # The _run targets exist only for compatibility w/ GYP.
 group("base_unittests_run") {
   testonly = true
   deps = [
     ":base_unittests",
   ]
 }
@@ skipping 319 matching lines @@
     deps += [ "//third_party/libevent" ]
   }
 
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
     set_sources_assignment_filter([])
     sources += [ "debug/proc_maps_linux_unittest.cc" ]
     set_sources_assignment_filter(sources_assignment_filter)
   }
 
-  if (is_win) {
+  if (is_win && target_cpu == "x64") {
     sources += [ "profiler/win32_stack_frame_unwinder_unittest.cc" ]
+    deps += [ ":base_profiler_test_support_library" ]
   }
 
   # 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.
   if (symbol_level > 0) {
     if (is_win) {
       data += [ "$root_out_dir/base_unittests.exe.pdb" ]
     } else if (is_mac) {
@@ skipping 140 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" ]
   }
 }