Deflake InstallReplacementWebAppApiTests by disabling legacy finalizer.

Tests were occasionally failing due to having an unexpected extra app
counted in ExtensionBrowserTest::InstallOrUpdateExtension. This was
because the test is awaiting the new BMO system to complete an install
but not the async legacy extension-based install that is fired
simultaneously by the new system. If the legacy install happens to
complete between counting num_before and num_after then we saw the web
app as an extra, unexpected installed extension.

Bug: 1094616
Change-Id: I2a14717e3f84102497c7a42c5b30bd6a5f868ed4
Fixed: 1094616
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2262357Reviewed-by: Alexey Baskakov <loyso@chromium.org>
Reviewed-by: Glen Robertson <glenrob@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Auto-Submit: Glen Robertson <glenrob@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781926}

chrome/browser/extensions/api/management/management_apitest.cc

@@ -18,6 +18,7 @@
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/web_applications/components/app_registrar.h"
 #include "chrome/browser/web_applications/components/app_shortcut_manager.h"
+#include "chrome/browser/web_applications/components/install_finalizer.h"
 #include "chrome/browser/web_applications/components/web_app_helpers.h"
 #include "chrome/browser/web_applications/components/web_app_provider_base.h"
 #include "chrome/browser/web_applications/test/test_web_app_ui_manager.h"
@@ -36,6 +37,7 @@
 #include "extensions/test/result_catcher.h"
 #include "extensions/test/test_extension_dir.h"
 #include "net/dns/mock_host_resolver.h"
+#include "testing/gtest/include/gtest/gtest.h"
 
 using extensions::Extension;
 using extensions::Manifest;
@@ -241,9 +243,12 @@ class InstallReplacementWebAppApiTest : public ExtensionManagementApiTest {
     chrome::SetAutoAcceptPWAInstallConfirmationForTesting(true);
     const GURL start_url = https_test_server_.GetURL(web_app_start_url);
     web_app::AppId web_app_id = web_app::GenerateAppIdFromURL(start_url);
-
     auto* provider =
         web_app::WebAppProviderBase::GetProviderBase(browser()->profile());
+    // Async legacy finalizer install was causing this test to be flaky (see
+    // crbug.com/1094616).
+    provider->install_finalizer().RemoveLegacyInstallFinalizerForTesting();
+
     EXPECT_FALSE(provider->registrar().IsLocallyInstalled(start_url));
     EXPECT_EQ(0, static_cast<int>(
                      provider->ui_manager().GetNumWindowsForApp(web_app_id)));

chrome/browser/web_applications/components/install_finalizer.h

@@ -98,6 +98,8 @@ class InstallFinalizer {
                            bool shortcut_created,
                            content::WebContents* web_contents);
 
+  virtual void RemoveLegacyInstallFinalizerForTesting() {}
+
   virtual void Start() {}
   virtual void Shutdown() {}
 

chrome/browser/web_applications/web_app_install_finalizer.cc

@@ -343,6 +343,10 @@ void WebAppInstallFinalizer::FinalizeUpdate(
     legacy_finalizer_->FinalizeUpdate(web_app_info, base::DoNothing());
 }
 
+void WebAppInstallFinalizer::RemoveLegacyInstallFinalizerForTesting() {
+  legacy_finalizer_ = nullptr;
+}
+
 void WebAppInstallFinalizer::Start() {
   DCHECK(!started_);
   started_ = true;

chrome/browser/web_applications/web_app_install_finalizer.h

@@ -50,6 +50,7 @@ class WebAppInstallFinalizer final : public InstallFinalizer {
   void UninstallExternalAppByUser(const AppId& app_id,
                                   UninstallWebAppCallback callback) override;
   bool WasExternalAppUninstalledByUser(const AppId& app_id) const override;
+  void RemoveLegacyInstallFinalizerForTesting() override;
   void Start() override;
   void Shutdown() override;