Enable Lookalike URLs interstitial by default

This CL enables the interstitial by default for lookalike domains in
user's navigation history (i.e. site engagement). Matching with top
domains is controlled by the topsites parameter.

Change-Id: Ib636fb4256de88b037549d964e9da551a1ddf592
Bug: 933520
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1674253Reviewed-by: Joe DeBlasio <jdeblasio@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Mustafa Emre Acer <meacer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672714}

chrome/browser/lookalikes/lookalike_url_navigation_throttle.cc

@@ -217,6 +217,15 @@ LookalikeUrlNavigationThrottle::~LookalikeUrlNavigationThrottle() {}
 
 ThrottleCheckResult LookalikeUrlNavigationThrottle::HandleThrottleRequest(
     const GURL& url) {
+  // Ignore if running unit tests. Some tests use
+  // TestMockTimeTaskRunner::ScopedContext and call CreateTestWebContents()
+  // which navigates and waits for throttles to complete using a RunLoop.
+  // However, TestMockTimeTaskRunner::ScopedContext disallows RunLoop so those
+  // tests crash. We should only do this with a real profile anyways.
+  if (profile_->AsTestingProfile()) {
+    return content::NavigationThrottle::PROCEED;
+  }
+
   content::NavigationHandle* handle = navigation_handle();
 
   // Ignore subframe and same document navigations.

chrome/common/chrome_features.cc

@@ -352,10 +352,9 @@ const base::Feature kViewsCastDialog{"ViewsCastDialog",
 
 // Enables navigation suggestions UI for lookalike URLs (e.g. internationalized
 // domain names that are visually similar to popular domains or to domains with
-// engagement score, such as googlé.com). This is prefixed with V2 because the
-// client logic handling the feature was changed.
+// engagement score, such as googlé.com).
 const base::Feature kLookalikeUrlNavigationSuggestionsUI{
-    "LookalikeUrlNavigationSuggestionsUI", base::FEATURE_DISABLED_BY_DEFAULT};
+    "LookalikeUrlNavigationSuggestionsUI", base::FEATURE_ENABLED_BY_DEFAULT};
 
 #if defined(OS_WIN) && defined(GOOGLE_CHROME_BUILD)
 // A feature that controls whether Chrome warns about incompatible applications.

testing/variations/fieldtrial_testing_config.json

@@ -2829,25 +2829,6 @@
             ]
         }
     ],
-    "LookalikeUrlNavigationSuggestionsUI": [
-        {
-            "platforms": [
-                "linux",
-                "mac",
-                "windows",
-                "android",
-                "chromeos"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "enable_features": [
-                        "LookalikeUrlNavigationSuggestionsUI"
-                    ]
-                }
-            ]
-        }
-    ],
     "LowPriorityIframes2": [
         {
             "platforms": [