Finch kill switch feature for background tab.

chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java
index 3b1ca31eea53835ed2dff211df11657603b48ac8..50535774e9cd267930d84b67c84ff9fe489b4823 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java
@@ -57,6 +57,7 @@ import org.chromium.base.test.util.Restriction;
 import org.chromium.base.test.util.RetryOnFailure;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ChromeTabbedActivity;
 import org.chromium.chrome.browser.IntentHandler;
@@ -93,6 +94,8 @@ import org.chromium.net.test.util.TestWebServer;
 import org.chromium.ui.mojom.WindowOpenDisposition;
 
 import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.Callable;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -1810,14 +1813,37 @@ public class CustomTabActivityTest extends CustomTabActivityTestBase {
         testSpeculateCorrectUrl(CustomTabsConnection.SpeculationParams.HIDDEN_TAB);
     }
 
+    /**
+     * Test that a hidden tab speculation is executed as a prerender if the |CCT_BACKGROUND_TAB|
+     * feature is disabled.
+     **/
+    @SmallTest
+    @Restriction(RESTRICTION_TYPE_NON_LOW_END_DEVICE)
+    @RetryOnFailure
+    public void testHiddenTabDisabled() throws Exception {
+        // One should be able to use @Features instead of calling
+        // ChromeFeatureList.setTestFeatures, but it doesn't appear to be effective.
+        // (perhaps a restriction due to running on Android?)
+        Map<String, Boolean> features = new HashMap<>();
+        features.put(ChromeFeatureList.CCT_BACKGROUND_TAB, false);
+        ChromeFeatureList.setTestFeatures(features);

[Benoit L, 2017/04/24 16:18:00]

Should this be reset in a finally block?

Seems that the annotation sets the list to null.

+        testSpeculateCorrectUrl(CustomTabsConnection.SpeculationParams.HIDDEN_TAB,
+                CustomTabsConnection.SpeculationParams.PRERENDER);
+    }
+
     private void testSpeculateCorrectUrl(int speculationMode) throws Exception {
+        testSpeculateCorrectUrl(speculationMode, speculationMode);
+    }
+
+    private void testSpeculateCorrectUrl(int requestedSpeculationMode, int usedSpeculationMode)
+            throws Exception {
         Context context = getInstrumentation().getTargetContext().getApplicationContext();
         final CustomTabsConnection connection = warmUpAndWait();
         CustomTabsSessionToken token = CustomTabsSessionToken.createDummySessionTokenForTesting();
         connection.newSession(token);
-        connection.setSpeculationModeForSession(token, speculationMode);
+        connection.setSpeculationModeForSession(token, requestedSpeculationMode);
         assertTrue(connection.mayLaunchUrl(token, Uri.parse(mTestPage), null, null));
-        ensureCompletedSpeculationForUrl(connection, mTestPage, speculationMode);
+        ensureCompletedSpeculationForUrl(connection, mTestPage, usedSpeculationMode);
 
         try {
             startCustomTabActivityWithIntent(CustomTabsTestUtils.createMinimalCustomTabIntent(