Make Prefetch flag and configuration accessible from Java.

Expose to Java Offline Prefetch flag and configurations to allow the
upcoming work on Android UI and settings to access them.

Bug: 850588
Change-Id: I697e944b57ebae57df73def9bffc8059b13eaa5d
Reviewed-on: https://chromium-review.googlesource.com/1154144Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579599}

chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java

@@ -247,6 +247,7 @@ public abstract class ChromeFeatureList {
             "OfflinePagesDescriptiveFailStatus";
     public static final String OFFLINE_PAGES_DESCRIPTIVE_PENDING_STATUS =
             "OfflinePagesDescriptivePendingStatus";
+    public static final String OFFLINE_PAGES_PREFETCHING = "OfflinePagesPrefetching";
     public static final String OMNIBOX_HIDE_SCHEME_DOMAIN_IN_STEADY_STATE =
             "OmniboxUIExperimentHideSteadyStateUrlSchemeAndSubdomains";
     public static final String OMNIBOX_SPARE_RENDERER = "OmniboxSpareRenderer";

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchConfiguration.java

+// Copyright 2018 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.
+
+package org.chromium.chrome.browser.offlinepages.prefetch;
+
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.chrome.browser.ChromeFeatureList;
+import org.chromium.chrome.browser.profiles.Profile;
+
+/**
+ * Allows the querying and setting of Offline Prefetch related configurations.
+ */
+@JNINamespace("offline_pages::android")
+public class PrefetchConfiguration {
+    /**
+     * Returns true if the Offline Prefetch feature flag is enabled. This can be used to determine
+     * if any evidence of this feature should be presented to the user (like its respective user
+     * settings entries).
+     */
+    public static boolean isPrefetchingFlagEnabled() {
+        return ChromeFeatureList.isEnabled(ChromeFeatureList.OFFLINE_PAGES_PREFETCHING);
+    }
+
+    /**
+     * Returns true if Offline Prefetch is allowed to run, requiring both the feature flag and the
+     * user setting to be true. If the current browser Profile is null this method returns false.
+     */
+    public static boolean isPrefetchingEnabled() {
+        return nativeIsPrefetchingEnabled(Profile.getLastUsedProfile());
+    }
+
+    /**
+     * Sets the value of the user controlled setting that controls whether Offline Prefetch is
+     * enabled or disabled. If the current browser Profile is null the setting will not be changed.
+     */
+    public static void setPrefetchingEnabledInSettings(boolean enabled) {
+        nativeSetPrefetchingEnabledInSettings(Profile.getLastUsedProfile(), enabled);
+    }
+
+    private static native boolean nativeIsPrefetchingEnabled(Profile profile);
+    private static native void nativeSetPrefetchingEnabledInSettings(
+            Profile profile, boolean enabled);
+}

chrome/android/java_sources.gni

@@ -922,6 +922,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/offlinepages/prefetch/OfflineNotificationBackgroundTask.java",
   "java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchBackgroundTask.java",
   "java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchBackgroundTaskScheduler.java",
+  "java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchConfiguration.java",
   "java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchPrefs.java",
   "java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchedPagesNotifier.java",
   "java/src/org/chromium/chrome/browser/omaha/ExponentialBackoffScheduler.java",
@@ -1871,6 +1872,7 @@ chrome_test_java_sources = [
   "javatests/src/org/chromium/chrome/browser/offlinepages/RecentTabsTest.java",
   "javatests/src/org/chromium/chrome/browser/offlinepages/indicator/OfflineIndicatorControllerTest.java",
   "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchBackgroundTaskTest.java",
+  "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchConfigurationTest.java",
   "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchFlowTest.java",
   "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/TestOfflinePageService.java",
   "javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/TestSuggestionsService.java",

chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchConfigurationTest.java

+// Copyright 2018 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.
+
+package org.chromium.chrome.browser.offlinepages.prefetch;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import android.support.test.filters.MediumTest;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.base.test.util.Feature;
+import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.ChromeFeatureList;
+import org.chromium.chrome.browser.ChromeSwitches;
+import org.chromium.chrome.test.ChromeActivityTestRule;
+import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
+import org.chromium.chrome.test.util.browser.Features;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/** Integration tests for {@link PrefetchConfiguration}. */
+@CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
+@RunWith(ChromeJUnit4ClassRunner.class)
+public class PrefetchConfigurationTest {
+    @Rule
+    public ChromeActivityTestRule<ChromeActivity> mActivityTestRule =
+            new ChromeActivityTestRule<>(ChromeActivity.class);
+
+    @Before
+    public void setUp() throws Exception {
+        // Start Chrome.
+        mActivityTestRule.startMainActivityOnBlankPage();
+    }
+
+    @Test
+    @MediumTest
+    @Feature("OfflinePrefetch")
+    @Features.EnableFeatures(ChromeFeatureList.OFFLINE_PAGES_PREFETCHING)
+    public void testWithPrefetchingFeatureEnabled() {
+        AtomicBoolean isFlagEnabled = new AtomicBoolean();
+        AtomicBoolean isEnabled = new AtomicBoolean();
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            isFlagEnabled.set(PrefetchConfiguration.isPrefetchingFlagEnabled());
+            isEnabled.set(PrefetchConfiguration.isPrefetchingEnabled());
+        });
+        assertTrue(isFlagEnabled.get());
+        assertTrue(isEnabled.get());
+
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            // Disable prefetching user setting.
+            PrefetchConfiguration.setPrefetchingEnabledInSettings(false);
+            isFlagEnabled.set(PrefetchConfiguration.isPrefetchingFlagEnabled());
+            isEnabled.set(PrefetchConfiguration.isPrefetchingEnabled());
+        });
+        assertTrue(isFlagEnabled.get());
+        assertFalse(isEnabled.get());
+
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            // Re-enable prefetching user setting.
+            PrefetchConfiguration.setPrefetchingEnabledInSettings(true);
+            isFlagEnabled.set(PrefetchConfiguration.isPrefetchingFlagEnabled());
+            isEnabled.set(PrefetchConfiguration.isPrefetchingEnabled());
+        });
+        assertTrue(isFlagEnabled.get());
+        assertTrue(isEnabled.get());
+    }
+
+    @Test
+    @MediumTest
+    @Feature("OfflinePrefetch")
+    @Features.DisableFeatures(ChromeFeatureList.OFFLINE_PAGES_PREFETCHING)
+    public void testWithPrefetchingFeatureDisabled() {
+        AtomicBoolean isFlagEnabled = new AtomicBoolean();
+        AtomicBoolean isEnabled = new AtomicBoolean();
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            isFlagEnabled.set(PrefetchConfiguration.isPrefetchingFlagEnabled());
+            isEnabled.set(PrefetchConfiguration.isPrefetchingEnabled());
+        });
+        assertFalse(isFlagEnabled.get());
+        assertFalse(isEnabled.get());
+
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            // Disable prefetching user setting.
+            PrefetchConfiguration.setPrefetchingEnabledInSettings(false);
+            isFlagEnabled.set(PrefetchConfiguration.isPrefetchingFlagEnabled());
+            isEnabled.set(PrefetchConfiguration.isPrefetchingEnabled());
+        });
+        assertFalse(isFlagEnabled.get());
+        assertFalse(isEnabled.get());
+
+        ThreadUtils.runOnUiThreadBlocking(() -> {
+            // Re-enable prefetching user setting.
+            PrefetchConfiguration.setPrefetchingEnabledInSettings(true);
+            isFlagEnabled.set(PrefetchConfiguration.isPrefetchingFlagEnabled());
+            isEnabled.set(PrefetchConfiguration.isPrefetchingEnabled());
+        });
+        assertFalse(isFlagEnabled.get());
+        assertFalse(isEnabled.get());
+    }
+}

chrome/browser/BUILD.gn

@@ -3959,6 +3959,7 @@ jumbo_split_static_library("browser") {
         "offline_pages/android/prefetch_background_task_android.cc",
         "offline_pages/android/prefetch_background_task_android.h",
         "offline_pages/android/prefetch_background_task_scheduler_android.cc",
+        "offline_pages/android/prefetch_configuration_impl_android.cc",
         "offline_pages/android/prefetched_pages_notifier_android.cc",
         "offline_pages/android/request_coordinator_factory.cc",
       ]
@@ -4522,6 +4523,7 @@ if (is_android) {
       "../android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/OfflineNotificationBackgroundTask.java",
       "../android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchBackgroundTask.java",
       "../android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchBackgroundTaskScheduler.java",
+      "../android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchConfiguration.java",
       "../android/java/src/org/chromium/chrome/browser/offlinepages/prefetch/PrefetchedPagesNotifier.java",
       "../android/java/src/org/chromium/chrome/browser/omnibox/AnswersImage.java",
       "../android/java/src/org/chromium/chrome/browser/omnibox/AutocompleteController.java",

chrome/browser/android/chrome_feature_list.cc

@@ -159,6 +159,7 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &offline_pages::kOfflinePagesDescriptiveFailStatusFeature,
     &offline_pages::kOfflinePagesDescriptivePendingStatusFeature,
     &offline_pages::kOfflinePagesSharingFeature,
+    &offline_pages::kPrefetchingOfflinePagesFeature,
     &omnibox::kUIExperimentHideSteadyStateUrlSchemeAndSubdomains,
     &password_manager::features::kPasswordExport,
     &password_manager::features::kPasswordSearchMobile,

chrome/browser/offline_pages/android/prefetch_configuration_impl_android.cc

+// Copyright 2018 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 "base/android/jni_android.h"
+#include "chrome/browser/offline_pages/prefetch/prefetch_configuration_impl.h"
+#include "chrome/browser/offline_pages/prefetch/prefetch_service_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_android.h"
+#include "components/offline_pages/core/prefetch/prefetch_service.h"
+#include "jni/PrefetchConfiguration_jni.h"
+
+using base::android::JavaParamRef;
+
+// These functions fulfill the Java to native link between
+// PrefetchConfiguration.java and PrefetchConfigurationImpl.
+
+namespace offline_pages {
+namespace android {
+
+namespace {
+
+PrefetchConfigurationImpl* PrefetchConfigurationImplFromJProfile(
+    const JavaParamRef<jobject>& jprofile) {
+  Profile* profile = ProfileAndroid::FromProfileAndroid(jprofile);
+  if (!profile)
+    return nullptr;
+
+  PrefetchService* prefetch_service =
+      PrefetchServiceFactory::GetForBrowserContext(profile);
+  if (!prefetch_service)
+    return nullptr;
+
+  // The cast below is safe because PrefetchConfigurationImpl is Chrome's
+  // implementation of PrefetchConfiguration.
+  return static_cast<PrefetchConfigurationImpl*>(
+      prefetch_service->GetPrefetchConfiguration());
+}
+
+}  // namespace
+
+JNI_EXPORT jboolean JNI_PrefetchConfiguration_IsPrefetchingEnabled(
+    JNIEnv* env,
+    const JavaParamRef<jclass>& jcaller,
+    const JavaParamRef<jobject>& jprofile) {
+  PrefetchConfigurationImpl* config_impl =
+      PrefetchConfigurationImplFromJProfile(jprofile);
+  if (config_impl)
+    return static_cast<jboolean>(config_impl->IsPrefetchingEnabled());
+  return false;
+}
+
+JNI_EXPORT void JNI_PrefetchConfiguration_SetPrefetchingEnabledInSettings(
+    JNIEnv* env,
+    const JavaParamRef<jclass>& jcaller,
+    const JavaParamRef<jobject>& jprofile,
+    jboolean enabled) {
+  PrefetchConfigurationImpl* config_impl =
+      PrefetchConfigurationImplFromJProfile(jprofile);
+  if (config_impl)
+    config_impl->SetPrefetchingEnabledInSettings(enabled);
+}
+
+}  // namespace android
+}  // namespace offline_pages