Add fake for InstanceIDWithSubtype.java, in order to re-use unit test

components/gcm_driver/instance_id/instance_id_driver_unittest.cc

 // Copyright 2015 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.
 
 #include "components/gcm_driver/instance_id/instance_id_driver.h"
 
 #include <stddef.h>
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h"
 #include "components/gcm_driver/instance_id/instance_id.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_ANDROID)
+#include "components/gcm_driver/instance_id/instance_id_android.h"
+#include "content/public/test/nested_message_pump_android.h"
+#endif  // OS_ANDROID
+
 namespace instance_id {
 
 namespace {
 
 const char kTestAppID1[] = "TestApp1";
 const char kTestAppID2[] = "TestApp2";
 const char kAuthorizedEntity1[] = "Sender 1";
 const char kAuthorizedEntity2[] = "Sender 2";
 const char kScope1[] = "GCM1";
 const char kScope2[] = "FooBar";
@@ skipping 14 matching lines @@
 }
 
 }  // namespace
 
 class InstanceIDDriverTest : public testing::Test {
  public:
   InstanceIDDriverTest();
   ~InstanceIDDriverTest() override;
 
   // testing::Test:
+  void TearDown() override;
   void SetUp() override;
 
   void WaitForAsyncOperation();
 
   // Recreates InstanceIDDriver to simulate restart.
   void RecreateInstanceIDDriver();
 
   // Sync wrappers for async version.
   std::string GetID(InstanceID* instance_id);
   base::Time GetCreationTime(InstanceID* instance_id);
@@ skipping 10 matching lines @@
 
   InstanceIDDriver* driver() const { return driver_.get(); }
 
  private:
   void GetIDCompleted(const std::string& id);
   void GetCreationTimeCompleted(const base::Time& creation_time);
   void DeleteIDCompleted(InstanceID::Result result);
   void GetTokenCompleted(const std::string& token, InstanceID::Result result);
   void DeleteTokenCompleted(InstanceID::Result result);
 
-  base::MessageLoopForUI message_loop_;
+  scoped_ptr<base::MessageLoop> message_loop_;
   scoped_ptr<FakeGCMDriverForInstanceID> gcm_driver_;
   scoped_ptr<InstanceIDDriver> driver_;
 
   std::string id_;
   base::Time creation_time_;
   std::string token_;
   InstanceID::Result result_;
 
   bool async_operation_completed_;
   base::Closure async_operation_completed_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDDriverTest);
 };
 
 InstanceIDDriverTest::InstanceIDDriverTest()
     : result_(InstanceID::UNKNOWN_ERROR),
       async_operation_completed_(false) {
+#if defined(OS_ANDROID)
+  // Need a NestedMessagePumpAndroid so WaitForAsyncOperation's RunLoop will run
+  // InstanceIDWithSubtype.java's AsyncTask onPostExecute methods.
+  message_loop_.reset(new base::MessageLoop(
+      scoped_ptr<base::MessagePump>(new content::NestedMessagePumpAndroid())));
+  static_cast<base::MessageLoopForUI*>(message_loop_.get())->Start();

[Peter Beverloo, 2016/04/11 14:57:05]

You're casting an instance of base::MessageLoop to a subclass you know it to not
be an instance of...?

[johnme, 2016/04/14 18:32:42]

Bizarrely, this seems to be what you're supposed to do. It's what Kristian does
in:

https://code.google.com/p/chromium/codesearch#chromium/src/base/android/java_...

And message_loop.h contains the following:

// Do not add any member variables to MessageLoopForUI!  This is important b/c
// MessageLoopForUI is often allocated via MessageLoop(TYPE_UI).  Any extra
// data that you need should be stored on the MessageLoop's pump_ instance.
static_assert(sizeof(MessageLoop) == sizeof(MessageLoopForUI),
              "MessageLoopForUI should not have extra member variables");

Anyway, thankfully this code all got removed now I stopped using
NestedMessagePumpAndroid.

+#else
+  message_loop_.reset(new base::MessageLoopForUI());
+#endif  // OS_ANDROID
 }
 
 InstanceIDDriverTest::~InstanceIDDriverTest() {
 }
 
 void InstanceIDDriverTest::SetUp() {
+#if defined(OS_ANDROID)
+  InstanceIDAndroid::ClearDataAndSetUseFakeForTesting(true);
+#endif  // OS_ANDROID
   gcm_driver_.reset(new FakeGCMDriverForInstanceID);
   RecreateInstanceIDDriver();
 }
 
+void InstanceIDDriverTest::TearDown() {
+#if defined(OS_ANDROID)
+  InstanceIDAndroid::ClearDataAndSetUseFakeForTesting(false);
+#endif  // OS_ANDROID
+}
+
 void InstanceIDDriverTest::RecreateInstanceIDDriver() {
   driver_.reset(new InstanceIDDriver(gcm_driver_.get()));
 }
 
 void InstanceIDDriverTest::WaitForAsyncOperation() {
   // No need to wait if async operation is not needed.
   if (async_operation_completed_)
     return;
   base::RunLoop run_loop;
   async_operation_completed_callback_ = run_loop.QuitClosure();
@@ skipping 229 matching lines @@
       GetToken(instance_id, kAuthorizedEntity1, kScope2, options);
   EXPECT_FALSE(new_token1.empty());
   EXPECT_NE(token1, new_token1);
 
   // The other token is not affected by the deletion.
   EXPECT_EQ(token2,
             GetToken(instance_id, kAuthorizedEntity2, kScope1, options));
 }
 
 }  // namespace instance_id