Disable PolicyTest.DisableScreenshotsFile test due to being flaky.

chrome/browser/policy/policy_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
 #include <string>
@@ skipping 2552 matching lines @@
 
   // Verify that the window cannot be toggled into fullscreen mode from within
   // Chrome (e.g., using keyboard accelerators).
   window->Fullscreen();
   EXPECT_FALSE(window->GetBaseWindow()->IsFullscreen());
 }
 #endif
 
 #if defined(OS_CHROMEOS)
 
-// Flaky http://crbug.com/476964
-#if defined(MEMORY_SANITIZER)
-#define MAYBE_DisableScreenshotsFile DISABLED_DisableScreenshotsFile
-#else
-#define MAYBE_DisableScreenshotsFile DisableScreenshotsFile
-#endif
-
-IN_PROC_BROWSER_TEST_F(PolicyTest, MAYBE_DisableScreenshotsFile) {
+// Flaky on MSan (crbug.com/476964) and regular Chrome OS (crbug.com/645769).
+IN_PROC_BROWSER_TEST_F(PolicyTest, DISABLED_DisableScreenshotsFile) {
   int screenshot_count = CountScreenshots();
 
   // Make sure screenshots are counted correctly.
   TestScreenshotFile(true);
   ASSERT_EQ(CountScreenshots(), screenshot_count + 1);
 
   // Check if trying to take a screenshot fails when disabled by policy.
   TestScreenshotFile(false);
   ASSERT_EQ(CountScreenshots(), screenshot_count + 1);
 }
@@ skipping 1795 matching lines @@
 
   SetEmptyPolicy();
   // Policy not set.
   CheckSystemTimezoneAutomaticDetectionPolicyUnset();
   EXPECT_TRUE(CheckResolveTimezoneByGeolocation(true, false));
   EXPECT_TRUE(manager->TimeZoneResolverShouldBeRunningForTests());
 }
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace policy