Expose always-on hotword preference via hotwordPrivate API.

BUG=397019

Review URL: https://codereview.chromium.org/555423002

Cr-Commit-Position: refs/heads/master@{#294314}

chrome/browser/extensions/api/hotword_private/hotword_private_api.cc

@@ -32,6 +32,10 @@ HotwordPrivateEventService::HotwordPrivateEventService(
       prefs::kHotwordSearchEnabled,
       base::Bind(&HotwordPrivateEventService::OnEnabledChanged,
                  base::Unretained(this)));
+  pref_change_registrar_.Add(
+      prefs::kHotwordAlwaysOnSearchEnabled,
+      base::Bind(&HotwordPrivateEventService::OnEnabledChanged,
+                 base::Unretained(this)));
 }
 
 HotwordPrivateEventService::~HotwordPrivateEventService() {
@@ -53,7 +57,8 @@ const char* HotwordPrivateEventService::service_name() {
 
 void HotwordPrivateEventService::OnEnabledChanged(
     const std::string& pref_name) {
-  DCHECK_EQ(pref_name, std::string(prefs::kHotwordSearchEnabled));
+  DCHECK(pref_name == std::string(prefs::kHotwordSearchEnabled) ||
+         pref_name == std::string(prefs::kHotwordAlwaysOnSearchEnabled));
   SignalEvent(OnEnabledChanged::kEventName);
 }
 
@@ -107,6 +112,8 @@ bool HotwordPrivateGetStatusFunction::RunSync() {
   PrefService* prefs = GetProfile()->GetPrefs();
   result.enabled_set = prefs->HasPrefPath(prefs::kHotwordSearchEnabled);
   result.enabled = prefs->GetBoolean(prefs::kHotwordSearchEnabled);
+  result.always_on_enabled =
+      prefs->GetBoolean(prefs::kHotwordAlwaysOnSearchEnabled);
   result.audio_logging_enabled = false;
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   result.experimental_hotword_enabled = command_line->HasSwitch(

chrome/browser/extensions/api/hotword_private/hotword_private_apitest.cc

@@ -165,6 +165,25 @@ IN_PROC_BROWSER_TEST_F(HotwordPrivateApiTest, IsAvailableFalse) {
   EXPECT_TRUE(listener.WaitUntilSatisfied());
 }
 
+IN_PROC_BROWSER_TEST_F(HotwordPrivateApiTest, AlwaysOnEnabled) {
+  {
+    ExtensionTestMessageListener listener("alwaysOnEnabled: false",
+                                          false);
+    ASSERT_TRUE(RunComponentExtensionTest("alwaysOnEnabled"))
+        << message_;
+    EXPECT_TRUE(listener.WaitUntilSatisfied());
+  }
+
+  profile()->GetPrefs()->SetBoolean(prefs::kHotwordAlwaysOnSearchEnabled, true);
+  {
+    ExtensionTestMessageListener listener("alwaysOnEnabled: true",
+                                          false);
+    ASSERT_TRUE(RunComponentExtensionTest("alwaysOnEnabled"))
+        << message_;
+    EXPECT_TRUE(listener.WaitUntilSatisfied());
+  }
+}
+
 IN_PROC_BROWSER_TEST_F(HotwordPrivateApiTest, ExperimentalHotwordEnabled) {
   // Disabled by default.
   ExtensionTestMessageListener listener("experimentalHotwordEnabled: false",
@@ -196,6 +215,11 @@ IN_PROC_BROWSER_TEST_F(HotwordPrivateApiTest, OnEnabledChanged) {
   ExtensionTestMessageListener listenerNotification("notification", false);
   profile()->GetPrefs()->SetBoolean(prefs::kHotwordSearchEnabled, true);
   EXPECT_TRUE(listenerNotification.WaitUntilSatisfied());
+
+  listenerNotification.Reset();
+  profile()->GetPrefs()->SetBoolean(prefs::kHotwordAlwaysOnSearchEnabled,
+                                    true);
+  EXPECT_TRUE(listenerNotification.WaitUntilSatisfied());
 }
 
 IN_PROC_BROWSER_TEST_F(HotwordPrivateApiTest, HotwordSession) {

chrome/common/extensions/api/hotword_private.idl

@@ -30,6 +30,9 @@
     // Whether experimental hotwording functionality is enabled. Mirrors the
     // "enable-experimental-hotwording" flag.
     boolean experimentalHotwordEnabled;
+
+    // Whether always-on hotwording is enabled.
+    boolean alwaysOnEnabled;
   };
 
   // The type of the recognized hotword. Right now it only has 'search' but

chrome/test/data/extensions/api_test/hotword_private/alwaysOnEnabled/manifest.json

+{
+  "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDCXAxIB5iu+XGtMYYJgSwMrqO+zNa3FlWeMJLOV+U1T2VL6wDU3WD9YNlioI6a6wG49AFquEbRxQwwxlvAZC1c95LBvRlnQAkEVum0KbrJ8WHTxxDEPOfITE0J1AP5j8V0WQ9jbYvUxgefIPhDPXHpdPRAxDotygTrPa33x1075wIDAQAB",
+  "name": "Hotword Private Test Extension",
+  "version": "0.1",
+  "manifest_version": 2,
+  "description": "Browser tests for chrome.hotword_private API",
+  "background" : {
+    "scripts": ["test.js"]
+  },
+  "permissions": ["hotwordPrivate"]
+}

chrome/test/data/extensions/api_test/hotword_private/alwaysOnEnabled/test.js

+// Copyright 2014 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.
+
+chrome.test.runTests([
+  function alwaysOnEnabled() {
+    chrome.hotwordPrivate.getStatus(
+        chrome.test.callbackPass(function(result) {
+          chrome.test.sendMessage("alwaysOnEnabled: " + result.alwaysOnEnabled);
+    }));
+  }
+]);