[Maintenance] Fix ComponentLoaderTests to properly handle destruction

of ProfileSyncService.

When a transitive dependency on ProfileSyncService was added to
hotwording, the LoadAll and AddOrReplace tests which load all component
extensions including hotwording now needed to load ProfileSyncService.
This resulted in a crash and as a temporary fix, sync was turned off in
these two tests.

We've now determined the proper fix which is to move the
TestBrowserThreadBundle to be the first member so that it is deleted
last. Previously, it was being deleted too soon and ProfileSyncService
could not be shut down properly since that service is multithreaded.

BUG=435629
TEST=Run ComponentLoaderTest.LoadAll or AddOrReplace and verify that it
does not crash or fail a DCHECK

Review URL: https://codereview.chromium.org/746943002

Cr-Commit-Position: refs/heads/master@{#305397}

1 files changed, 1 insertions, 10 deletions

diff --git a/chrome/browser/extensions/component_loader_unittest.cc b/chrome/browser/extensions/component_loader_unittest.cc
index 7435928..c8625b1 100644
--- a/chrome/browser/extensions/component_loader_unittest.cc
+++ b/chrome/browser/extensions/component_loader_unittest.cc
@@ -105,6 +105,7 @@ class ComponentLoaderTest : public testing::Test {
   }
 
  protected:
+  content::TestBrowserThreadBundle thread_bundle_;
   TestingProfile profile_;
   MockExtensionService extension_service_;
   TestingPrefServiceSyncable prefs_;
@@ -117,8 +118,6 @@ class ComponentLoaderTest : public testing::Test {
   // The contents of the text extension's manifest file.
   std::string manifest_contents_;
 
-  content::TestBrowserThreadBundle thread_bundle_;
-
   base::FilePath GetBasePath() {
     base::FilePath test_data_dir;
     PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir);
@@ -224,10 +223,6 @@ TEST_F(ComponentLoaderTest, Remove) {
 }
 
 TEST_F(ComponentLoaderTest, LoadAll) {
-  // This loads the hotword component extension which has a dependency on sync.
-  // However, this doesn't work with unittests so disable sync.
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(switches::kDisableSync);
-
   extension_service_.set_ready(false);
   ExtensionRegistry* registry = ExtensionRegistry::Get(&profile_);
 
@@ -249,10 +244,6 @@ TEST_F(ComponentLoaderTest, LoadAll) {
 }
 
 TEST_F(ComponentLoaderTest, AddOrReplace) {
-  // This loads the hotword component extension which has a dependency on sync.
-  // However, this doesn't work with unittests so disable sync.
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(switches::kDisableSync);
-
   EXPECT_EQ(0u, component_loader_.registered_extensions_count());
   component_loader_.AddDefaultComponentExtensions(false);
   size_t const default_count = component_loader_.registered_extensions_count();