[omnibox] Fix LocalHistoryZeroSuggestProviderTest shutdown order

LocalHistoryZeroSuggestProviderTest uses a
FakeAutocompleteProviderClient, but that class requires a very
particular creation an destruction sequence.

This CL fixes this problem, which was causing issues on ASAN bots.

In the future we should fix the FakeAutocompleteProviderClient API to
make it more obvious that it has special creation destruction
requirements.

Bug: 1010691
Change-Id: Ia5b11b548720fade377e1f9c573105213e71f975
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1845991
Commit-Queue: Tommy Li <tommycli@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703427}

components/omnibox/browser/local_history_zero_suggest_provider_unittest.cc

@@ -56,25 +56,30 @@ class LocalHistoryZeroSuggestProviderTest
     : public testing::Test,
       public AutocompleteProviderListener {
  public:
-  LocalHistoryZeroSuggestProviderTest()
-      : client_(std::make_unique<FakeAutocompleteProviderClient>()),
-        provider_(base::WrapRefCounted(
-            LocalHistoryZeroSuggestProvider::Create(client_.get(), this))) {
-    SetZeroSuggestVariant(
-        metrics::OmniboxEventProto::NTP_REALBOX,
-        LocalHistoryZeroSuggestProvider::kZeroSuggestLocalVariant);
-  }
-  ~LocalHistoryZeroSuggestProviderTest() override {}
+  LocalHistoryZeroSuggestProviderTest() = default;
+  ~LocalHistoryZeroSuggestProviderTest() override = default;
 
  protected:
   // testing::Test
   void SetUp() override {
+    client_ = std::make_unique<FakeAutocompleteProviderClient>();
+    provider_ = base::WrapRefCounted(
+        LocalHistoryZeroSuggestProvider::Create(client_.get(), this));
+
+    SetZeroSuggestVariant(
+        metrics::OmniboxEventProto::NTP_REALBOX,
+        LocalHistoryZeroSuggestProvider::kZeroSuggestLocalVariant);
+
     // Verify that Google is the default search provider.
     ASSERT_EQ(SEARCH_ENGINE_GOOGLE,
               default_search_provider()->GetEngineType(
                   client_->GetTemplateURLService()->search_terms_data()));
   }
-  void TearDown() override { task_environment_.RunUntilIdle(); }
+  void TearDown() override {
+    provider_ = nullptr;
+    client_.reset();
+    task_environment_.RunUntilIdle();
+  }
 
   // AutocompleteProviderListener
   void OnProviderUpdate(bool updated_matches) override;