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

components/gcm_driver/instance_id/instance_id_driver_unittest.cc

Index: components/gcm_driver/instance_id/instance_id_driver_unittest.cc
diff --git a/components/gcm_driver/instance_id/instance_id_driver_unittest.cc b/components/gcm_driver/instance_id/instance_id_driver_unittest.cc
index 8997296aca9b1dad49e6749524421ca3094672b6..63fba0f57a89fcbddab981cc46e8f805d95522f9 100644
--- a/components/gcm_driver/instance_id/instance_id_driver_unittest.cc
+++ b/components/gcm_driver/instance_id/instance_id_driver_unittest.cc
@@ -17,6 +17,11 @@
 #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 "components/gcm_driver/instance_id/instance_id_test_utils_android.h"
+#endif  // OS_ANDROID
+
 namespace instance_id {
 
 namespace {
@@ -52,6 +57,7 @@ class InstanceIDDriverTest : public testing::Test {
 
   // testing::Test:
   void SetUp() override;
+  void TearDown() override;
 
   void WaitForAsyncOperation();
 
@@ -105,10 +111,21 @@ InstanceIDDriverTest::~InstanceIDDriverTest() {
 }
 
 void InstanceIDDriverTest::SetUp() {
+#if defined(OS_ANDROID)
+  InstanceIDAndroid::SetBlockOnAsyncTasksForTesting(true);
+  InstanceIDTestUtilsAndroid::ClearDataAndSetUseFakeForTesting(true);

[Peter Beverloo, 2016/04/18 15:46:36]

Would we ever used them separately? Could trigger
InstanceIDAndroid::SetBlockOnAsyncTasksForTesting from
InstanceIDTestUtilsAndroid otherwise.

Could also make one of these super awesome scoped objects that do this
automagically for you :P

[johnme, 2016/04/19 11:15:43]

I made them scoped objects. I left them separate for now, since it would be
reasonable for tests to use ScopedUseFakeInstanceIDAndroid but not
ScopedBlockOnAsyncTasksForTesting if they have a nested Java loop like the
upcoming Android browser_tests presumably will, (or
ScopedBlockOnAsyncTasksForTesting but not ScopedUseFakeInstanceIDAndroid if they
want to test against live GCM, but don't have a nested Java loop).

+#endif  // OS_ANDROID
   gcm_driver_.reset(new FakeGCMDriverForInstanceID);
   RecreateInstanceIDDriver();
 }
 
+void InstanceIDDriverTest::TearDown() {
+#if defined(OS_ANDROID)
+  InstanceIDTestUtilsAndroid::ClearDataAndSetUseFakeForTesting(false);
+  InstanceIDAndroid::SetBlockOnAsyncTasksForTesting(false);
+#endif  // OS_ANDROID
+}
+
 void InstanceIDDriverTest::RecreateInstanceIDDriver() {
   driver_.reset(new InstanceIDDriver(gcm_driver_.get()));
 }