Enable lock screen note taking for dev channel

Enables lock scree apps for dev channel, and adds a flag that can
be used to enable the feature to chrome://flags:
 *  enable-lock-screen-apps enables lock screen apps

BUG=715781

Change-Id: I3a4638d16af1585b6c18445ee7f405e55b0c2db5
Reviewed-on: https://chromium-review.googlesource.com/576658Reviewed-by: Rahul Chaturvedi <rkc@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Toni Barzic <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487945}

chrome/browser/about_flags.cc

@@ -3208,6 +3208,12 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(midi::features::kMidiManagerCros)},
 #endif  // defined(OS_CHROMEOS)
 
+#if defined(OS_CHROMEOS)
+    {"enable-lock-screen-apps", flag_descriptions::kEnableLockScreenAppsName,
+     flag_descriptions::kEnableLockScreenAppsDescription, kOsCrOS,
+     SINGLE_VALUE_TYPE(chromeos::switches::kEnableLockScreenApps)},
+#endif  // defined(OS_CHROMEOS)
+
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms/enums.xml. See note in
     // enums.xml and don't forget to run AboutFlagsHistogramTest unit test.

chrome/browser/chromeos/note_taking_helper_unittest.cc

@@ -584,12 +584,12 @@ TEST_P(NoteTakingHelperTest,
                       lock_enabled_action_handler->CreateDeepCopy());
   InstallExtension(dev_extension.get(), profile());
 
-  // Install third-party app that supports lock screen note taking.
+  // Install third-party app that doesn't support lock screen note taking.
   const extensions::ExtensionId kNewNoteId = crx_file::id_util::GenerateId("a");
   const std::string kName = "Some App";
-  scoped_refptr<const extensions::Extension> has_new_note = CreateExtension(
-      kNewNoteId, kName, extensions::ListBuilder().Append("lockScreen").Build(),
-      lock_enabled_action_handler->CreateDeepCopy());
+  scoped_refptr<const extensions::Extension> has_new_note =
+      CreateExtension(kNewNoteId, kName, extensions::ListBuilder().Build(),
+                      lock_enabled_action_handler->CreateDeepCopy());
   InstallExtension(has_new_note.get(), profile());
 
   // Verify that only Keep app is reported to support lock screen note taking.

chrome/browser/flag_descriptions.cc

@@ -2555,6 +2555,13 @@ const char kForceEnableStylusToolsDescription[] =
     "Forces display of the stylus tools menu in the shelf and the stylus "
     "section in settings, even if there is no attached stylus device.";
 
+const char kEnableLockScreenAppsName[] = "Enable lock screen note taking";
+
+const char kEnableLockScreenAppsDescription[] =
+    "Enable new-note action handler apps on the lock screen. The user will be "
+    "able to launch the preferred note-taking action from the lock screen, "
+    "provided that the app supports lock screen note taking.";
+
 //  Network portal notification
 
 const char kNetworkPortalNotificationName[] =

chrome/browser/flag_descriptions.h

@@ -1302,6 +1302,9 @@ extern const char kEnableEncryptionMigrationDescription[];
 extern const char kEnableImeMenuName[];
 extern const char kEnableImeMenuDescription[];
 
+extern const char kEnableLockScreenAppsName[];
+extern const char kEnableLockScreenAppsDescription[];
+
 extern const char kEnableTouchSupportForScreenMagnifierName[];
 extern const char kEnableTouchSupportForScreenMagnifierDescription[];
 

extensions/common/api/_permission_features.json

@@ -298,15 +298,21 @@
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app", "platform_app"]
   },
-  "lockScreen": {
-    "channel": "trunk",
+  "lockScreen": [{
+    "channel": "dev",
     "extension_types": ["platform_app"],
     "platforms": ["chromeos"],
     "whitelist":  [
       "6F9C741B8E0E546652134F1138DF0284A7C9B21E",  // http://crbug.com/728309
       "47448626CB266C60AA2404E4EB426E025DF497DF"   // http://crbug.com/728309
     ]
-  },
+  }, {
+    // TODO(tbarzic): Remove this once the apps in the white-list can be used
+    // to test lock screen note taking.
+    "channel": "dev",
+    "extension_types": ["platform_app"],
+    "platforms": ["chromeos"]
+  }],
   "mediaPerceptionPrivate": [{
     "channel": "stable",
     "extension_types": ["platform_app"],

tools/metrics/histograms/enums.xml

@@ -23418,6 +23418,7 @@ from previous Chrome versions.
   <int value="841343322" label="disable-new-korean-ime"/>
   <int value="842432903" label="CaptureThumbnailOnNavigatingAway:enabled"/>
   <int value="846951416" label="CopylessPaste:enabled"/>
+  <int value="848324390" label="enable-lock-screen-apps"/>
   <int value="851085848" label="enable-settings-window"/>
   <int value="854730848" label="disable-app-info-dialog-mac"/>
   <int value="855746780" label="disable-physical-keyboard-autocorrect"/>