Enable building with a small set of JNI related files required for linking content_unittests.

base/test/test_stub_android.cc

Index: base/test/test_stub_android.cc
diff --git a/base/test/test_stub_android.cc b/base/test/test_stub_android.cc
index 82e645e7a52f7b292bbd923e471a3719bd84ece1..b236feef158586439bc983d7e1b4ba29a3bbef87 100644
--- a/base/test/test_stub_android.cc
+++ b/base/test/test_stub_android.cc
@@ -179,17 +179,8 @@ void InitAndroidTestStub() {
   MessageLoop::InitMessagePumpForUIFactory(&CreateMessagePumpForUIStub);
 }
 
-// TODO(michaelbai): The below DetachFromVM was added because we excluded the
-// jni_android.{h|cc} which require JNI to compile. Remove them when those 2
-// files added.
 namespace base {
 
-namespace android {
-
-void DetachFromVM() {}
-
-}  // namespace android
-
 // TODO(michaelbai): The below MessagePumpForUI were added because we excluded
 // message_pump_android.{h|cc} which require JNI to compile. Remove them when
 // those 2 files added.