Fix DeepScanningDialogViewsCancelPendingScanBrowserTest flakiness

The test was flaky less than 1% of the time because of a race between
the "Cancel" button click propagating and the scan responses. The fix is
to set up the delegate so that those responses never come back.

Bug: 1059060
Change-Id: I5d6dd17bfe76f8a2120e3a8cd1cb312f8f5c1fac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2090135Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Dominique Fauteux-Chapleau <domfc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747792}

chrome/browser/safe_browsing/cloud_content_scanning/deep_scanning_browsertest_base.cc

@@ -25,6 +25,39 @@ constexpr base::TimeDelta kMinimumPendingDelay =
 constexpr base::TimeDelta kSuccessTimeout =
     base::TimeDelta::FromMilliseconds(100);
 
+class UnresponsiveDeepScanningDialogDelegate
+    : public FakeDeepScanningDialogDelegate {
+ public:
+  using FakeDeepScanningDialogDelegate::FakeDeepScanningDialogDelegate;
+
+  static std::unique_ptr<DeepScanningDialogDelegate> Create(
+      base::RepeatingClosure delete_closure,
+      StatusCallback status_callback,
+      EncryptionStatusCallback encryption_callback,
+      std::string dm_token,
+      content::WebContents* web_contents,
+      Data data,
+      CompletionCallback callback) {
+    auto ret = std::make_unique<UnresponsiveDeepScanningDialogDelegate>(
+        delete_closure, status_callback, encryption_callback,
+        std::move(dm_token), web_contents, std::move(data),
+        std::move(callback));
+    return ret;
+  }
+
+ private:
+  void UploadTextForDeepScanning(
+      std::unique_ptr<BinaryUploadService::Request> request) override {
+    // Do nothing.
+  }
+
+  void UploadFileForDeepScanning(
+      const base::FilePath& path,
+      std::unique_ptr<BinaryUploadService::Request> request) override {
+    // Do nothing.
+  }
+};
+
 }  // namespace
 
 DeepScanningBrowserTestBase::DeepScanningBrowserTestBase() {
@@ -79,6 +112,17 @@ void DeepScanningBrowserTestBase::SetUpDelegate() {
       kDmToken));
 }
 
+void DeepScanningBrowserTestBase::SetUpUnresponsiveDelegate() {
+  SetDMTokenForTesting(policy::DMToken::CreateValidTokenForTesting(kDmToken));
+  DeepScanningDialogDelegate::SetFactoryForTesting(base::BindRepeating(
+      &UnresponsiveDeepScanningDialogDelegate::Create, base::DoNothing(),
+      base::Bind(&DeepScanningBrowserTestBase::StatusCallback,
+                 base::Unretained(this)),
+      base::Bind(&DeepScanningBrowserTestBase::EncryptionStatusCallback,
+                 base::Unretained(this)),
+      kDmToken));
+}
+
 void DeepScanningBrowserTestBase::SetQuitClosure(
     base::RepeatingClosure quit_closure) {
   quit_closure_ = quit_closure;

chrome/browser/safe_browsing/cloud_content_scanning/deep_scanning_browsertest_base.h

@@ -29,6 +29,9 @@ class DeepScanningBrowserTestBase : public InProcessBrowserTest {
   // and EncryptionStatusCallback. Also sets up a test DM token.
   void SetUpDelegate();
 
+  // Sets up a FakeDeepScanningDialogDelegate that never returns responses.
+  void SetUpUnresponsiveDelegate();
+
   // Set up a quit closure to be called by the test. This is useful to control
   // when the test ends.
   void SetQuitClosure(base::RepeatingClosure quit_closure);

chrome/browser/safe_browsing/cloud_content_scanning/deep_scanning_dialog_views_browsertest.cc

@@ -507,13 +507,8 @@ INSTANTIATE_TEST_SUITE_P(
         /*response_delay*/
         testing::Values(kNoDelay, kSmallDelay, kNormalDelay)));
 
-#if defined(OS_MACOSX)
-#define MAYBE_Test DISABLED_Test
-#else
-#define MAYBE_Test Test
-#endif
 IN_PROC_BROWSER_TEST_F(DeepScanningDialogViewsCancelPendingScanBrowserTest,
-                       MAYBE_Test) {
+                       Test) {
   // Setup policies to enable deep scanning, its UI and the responses to be
   // simulated.
   SetDlpPolicy(CHECK_UPLOADS);
@@ -523,9 +518,10 @@ IN_PROC_BROWSER_TEST_F(DeepScanningDialogViewsCancelPendingScanBrowserTest,
   // Always set this policy so the UI is shown.
   SetWaitPolicy(DELAY_UPLOADS);
 
-  // Set up delegate test values.
+  // Set up delegate test values. An unresponsive delegate is set up to avoid
+  // a race between the file responses and the "Cancel" button being clicked.
   FakeDeepScanningDialogDelegate::SetResponseDelay(kSmallDelay);
-  SetUpDelegate();
+  SetUpUnresponsiveDelegate();
 
   bool called = false;
   base::RunLoop run_loop;