Add feature flag for sharing canonical URLs.

Adds a feature flag to control whether the canonical URL is shared.

Bug: none
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I5b70667ab1743af8ea5845f541dfc0f621ba9314
Reviewed-on: https://chromium-review.googlesource.com/744973
Commit-Queue: Peter Lee <pkl@chromium.org>
Reviewed-by: Peter Lee <pkl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512762}

ios/chrome/browser/BUILD.gn

@@ -123,6 +123,7 @@ source_set("browser") {
     "//ios/chrome/browser/payments:constants",
     "//ios/chrome/browser/ssl:features",
     "//ios/chrome/browser/sync/glue",
+    "//ios/chrome/browser/ui/activity_services:features",
     "//ios/chrome/browser/ui/external_search:features",
     "//ios/chrome/browser/ui/history:history_base_feature",
     "//ios/chrome/browser/ui/main:feature_flags",

ios/chrome/browser/about_flags.mm

@@ -39,6 +39,7 @@
 #include "ios/chrome/browser/drag_and_drop/drag_and_drop_flag.h"
 #include "ios/chrome/browser/ios_chrome_flag_descriptions.h"
 #include "ios/chrome/browser/ssl/captive_portal_features.h"
+#include "ios/chrome/browser/ui/activity_services/canonical_url_feature.h"
 #include "ios/chrome/browser/ui/external_search/features.h"
 #import "ios/chrome/browser/ui/history/history_base_feature.h"
 #include "ios/chrome/browser/ui/main/main_feature_flags.h"
@@ -193,6 +194,9 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
     {"slim-navigation-manager", flag_descriptions::kSlimNavigationManagerName,
      flag_descriptions::kSlimNavigationManagerDescription, flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(web::features::kSlimNavigationManager)},
+    {"ios-share-canonical-url", flag_descriptions::kShareCanonicalURLName,
+     flag_descriptions::kShareCanonicalURLDescription, flags_ui::kOsIos,
+     FEATURE_VALUE_TYPE(activity_services::kShareCanonicalURL)},
 };
 
 // Add all switches from experimental flags to |command_line|.

ios/chrome/browser/ios_chrome_flag_descriptions.cc

@@ -78,6 +78,11 @@ extern const char kSafeAreaCompatibleToolbarName[] =
 extern const char kSafeAreaCompatibleToolbarDescription[] =
     "When enabled, the toolbar resizes itself when the safe area changes.";
 
+const char kShareCanonicalURLName[] = "Share Canonical URL";
+const char kShareCanonicalURLDescription[] =
+    "When enabled, the current page's canonical URL is shared (if it exists) "
+    "instead of the visible URL.";
+
 const char kSlimNavigationManagerName[] = "Use Slim Navigation Manager";
 const char kSlimNavigationManagerDescription[] =
     "When enabled, uses the experimental slim navigation manager that provides "

ios/chrome/browser/ios_chrome_flag_descriptions.h

@@ -70,6 +70,11 @@ extern const char kPhysicalWebDescription[];
 extern const char kSafeAreaCompatibleToolbarName[];
 extern const char kSafeAreaCompatibleToolbarDescription[];
 
+// Title and description for the flag to share the canonical URL of the
+// current page instead of the visible URL.
+extern const char kShareCanonicalURLName[];
+extern const char kShareCanonicalURLDescription[];
+
 // Title and description for the flag to enable WKBackForwardList based
 // navigation manager.
 extern const char kSlimNavigationManagerName[];

ios/chrome/browser/ui/activity_services/BUILD.gn

@@ -119,3 +119,14 @@ source_set("eg_tests") {
   ]
   libs = [ "XCTest.framework" ]
 }
+
+source_set("features") {
+  configs += [ "//build/config/compiler:enable_arc" ]
+  sources = [
+    "canonical_url_feature.cc",
+    "canonical_url_feature.h",
+  ]
+  deps = [
+    "//base",
+  ]
+}

ios/chrome/browser/ui/activity_services/canonical_url_feature.cc

+// Copyright 2017 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.
+
+#import "ios/chrome/browser/ui/activity_services/canonical_url_feature.h"
+
+namespace activity_services {
+
+const base::Feature kShareCanonicalURL{"ShareCanonicalURLIOS",
+                                       base::FEATURE_DISABLED_BY_DEFAULT};
+
+}  // namespace activity_services

ios/chrome/browser/ui/activity_services/canonical_url_feature.h

+// Copyright 2017 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_ACTIVITY_SERVICES_CANONICAL_URL_FEATURE_H_
+#define IOS_CHROME_BROWSER_UI_ACTIVITY_SERVICES_CANONICAL_URL_FEATURE_H_
+
+#include "base/feature_list.h"
+
+namespace activity_services {
+
+// Used to control whether the canonical URL is shared if available.
+extern const base::Feature kShareCanonicalURL;
+
+}  // namespace activity_services
+
+#endif  // IOS_CHROME_BROWSER_UI_ACTIVITY_SERVICES_CANONICAL_URL_FEATURE_H_