Add base_unittests to win8 trybot. Fix PEImage tests.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index 045878c555f1052fd3f29d7b4e86dd8561b2916b..5cd5a5db7e910d7e3b582b7da7087947b5adc11d 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1135,6 +1135,23 @@ source_set("protect_file_posix") {
   ]
 }
 
+if (is_win) {
+  shared_library("pe_image_test") {
+    sources = [
+      "win/pe_image_test.cc",
+    ]
+    ldflags = [
+      "/DELAYLOAD:cfgmgr32.dll",
+      "/DELAYLOAD:shell32.dll",
+      "/SUBSYSTEM:WINDOWS",
+    ]
+    libs = [
+      "cfgmgr32.lib",
+      "shell32.lib",
+    ]
+  }
+}
+
 test("base_unittests") {
   sources = [
     "android/application_status_listener_unittest.cc",
@@ -1442,6 +1459,10 @@ test("base_unittests") {
     set_sources_assignment_filter(sources_assignment_filter)
   }
 
+  if (is_win) {
+    deps += [ ":pe_image_test" ]
+  }
+
   # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }