Introduce restricted PasswordFormManager::GrabFetcher

components/password_manager/core/browser/password_form_manager_unittest.cc

Index: components/password_manager/core/browser/password_form_manager_unittest.cc
diff --git a/components/password_manager/core/browser/password_form_manager_unittest.cc b/components/password_manager/core/browser/password_form_manager_unittest.cc
index 8450eb129264039b909c9d1c23364f4a29ff7b89..e2532847a87a73a10a089fb616086651373a9c5d 100644
--- a/components/password_manager/core/browser/password_form_manager_unittest.cc
+++ b/components/password_manager/core/browser/password_form_manager_unittest.cc
@@ -98,6 +98,11 @@ class MockFormSaver : public StubFormSaver {
   DISALLOW_COPY_AND_ASSIGN(MockFormSaver);
 };
 
+class MockFormFetcher : public FakeFormFetcher {
+ public:
+  MOCK_METHOD1(AddConsumer, void(Consumer*));
+};
+
 MATCHER_P(CheckUsername, username_value, "Username incorrect") {
   return arg.username_value == username_value;
 }
@@ -2959,4 +2964,18 @@ TEST_F(PasswordFormManagerTest, ResetStoredMatches) {
   EXPECT_THAT(credentials_to_update, IsEmpty());
 }
 
+// Check that if asked to take ownership of the same FormFetcher which it had
+// consumed before, the PasswordFormManager does not add itself as a consumer
+// again.
+TEST_F(PasswordFormManagerTest, GrabFetcher_Same) {
+  auto fetcher = base::MakeUnique<MockFormFetcher>();
+  fetcher->Fetch();
+  PasswordFormManager form_manager(
+      password_manager(), client(), client()->driver(), *observed_form(),
+      base::MakeUnique<MockFormSaver>(), fetcher.get());
+
+  EXPECT_CALL(*fetcher, AddConsumer(_)).Times(0);
+  form_manager.GrabFetcher(std::move(fetcher));
+}
+
 }  // namespace password_manager