Fix flaky test ContentSerializedNavigationBuilderTest.ToNavigationEntry

components/sessions/content/content_serialized_navigation_builder_unittest.cc

Index: components/sessions/content/content_serialized_navigation_builder_unittest.cc
diff --git a/components/sessions/content/content_serialized_navigation_builder_unittest.cc b/components/sessions/content/content_serialized_navigation_builder_unittest.cc
index 5f402982435e72c63e92c029be725b0a11911c3f..c48dc962dfb7e142a75f5434a6e984eae7f66aa9 100644
--- a/components/sessions/content/content_serialized_navigation_builder_unittest.cc
+++ b/components/sessions/content/content_serialized_navigation_builder_unittest.cc
@@ -87,20 +87,32 @@ void SetExtendedInfoForTest(content::NavigationEntry* entry) {
                       base::ASCIIToUTF16(kExtendedInfoValue1));
   entry->SetExtraData(kExtendedInfoKey2,
                       base::ASCIIToUTF16(kExtendedInfoValue2));
-  ContentSerializedNavigationDriver::GetInstance()->RegisterExtendedInfoHandler(
-      kExtendedInfoKey1, base::WrapUnique<ExtendedInfoHandler>(
-                             new TestExtendedInfoHandler(kExtendedInfoKey1)));
-  ContentSerializedNavigationDriver::GetInstance()->RegisterExtendedInfoHandler(
-      kExtendedInfoKey2, base::WrapUnique<ExtendedInfoHandler>(
-                             new TestExtendedInfoHandler(kExtendedInfoKey2)));
 }
 
 }  // namespace
 
+class ContentSerializedNavigationBuilderTest : public testing::Test {
+ public:
+  ContentSerializedNavigationBuilderTest() {}
+  ~ContentSerializedNavigationBuilderTest() override {}
+
+  static void SetUpTestCase() {
+    ContentSerializedNavigationDriver::GetInstance()->

[sky, 2016/10/06 17:01:47]

While this works for your test, it means any other test that runs after yours
gets state your test installed. I would prefer you add a reset function on
ContentSerializedNavigationDriver that is private and friended by this test that
clears the map on setup/teardown.

[jianli, 2016/10/06 23:54:50]

Done.

+    RegisterExtendedInfoHandler(
+        kExtendedInfoKey1,
+        base::WrapUnique<ExtendedInfoHandler>(
+            new TestExtendedInfoHandler(kExtendedInfoKey1)));
+    ContentSerializedNavigationDriver::GetInstance()->
+    RegisterExtendedInfoHandler(
+        kExtendedInfoKey2,
+        base::WrapUnique<ExtendedInfoHandler>(
+            new TestExtendedInfoHandler(kExtendedInfoKey2)));
+  }
+};
 
 // Create a SerializedNavigationEntry from a NavigationEntry.  All its fields
 // should match the NavigationEntry's.
-TEST(ContentSerializedNavigationBuilderTest, FromNavigationEntry) {
+TEST_F(ContentSerializedNavigationBuilderTest, FromNavigationEntry) {
   const std::unique_ptr<content::NavigationEntry> navigation_entry(
       MakeNavigationEntryForTest());
   SetExtendedInfoForTest(navigation_entry.get());
@@ -146,7 +158,7 @@ TEST(ContentSerializedNavigationBuilderTest, FromNavigationEntry) {
 // a SerializedNavigationEntry and back.  The new one should match the old one
 // except for fields that aren't preserved, which should be set to
 // expected values.
-TEST(ContentSerializedNavigationBuilderTest, ToNavigationEntry) {
+TEST_F(ContentSerializedNavigationBuilderTest, ToNavigationEntry) {
   const std::unique_ptr<content::NavigationEntry> old_navigation_entry(
       MakeNavigationEntryForTest());
   SetExtendedInfoForTest(old_navigation_entry.get());
@@ -197,7 +209,7 @@ TEST(ContentSerializedNavigationBuilderTest, ToNavigationEntry) {
   EXPECT_EQ(kExtendedInfoValue2, base::UTF16ToASCII(extra_data));
 }
 
-TEST(ContentSerializedNavigationBuilderTest, SetPasswordState) {
+TEST_F(ContentSerializedNavigationBuilderTest, SetPasswordState) {
   std::unique_ptr<content::NavigationEntry> entry(
       content::NavigationEntry::Create());