Add experimental support for the hrefTranslate attribute.

This adds the plumbing that exposes the attribute dynamically. So that
it is only bound when a translate service is available. The translate
team will hook into the frame load request to grab the attribute
from the anchor.

Doc: https://github.com/dtapuska/html-translate
Intent to Implement: https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/hmASm1yhi5s/7vqmt7CwDgAJ

BUG=872777

Change-Id: I0004fe33afeaf3255031bc87f47c7f4d1209ffc8
Reviewed-on: https://chromium-review.googlesource.com/1175031
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: anthonyvd <anthonyvd@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587580}

chrome/browser/chrome_content_browser_client.cc

@@ -119,6 +119,7 @@
 #include "chrome/browser/sync_file_system/local/sync_file_system_backend.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "chrome/browser/tracing/chrome_tracing_delegate.h"
+#include "chrome/browser/translate/translate_service.h"
 #include "chrome/browser/ui/blocked_content/blocked_window_params.h"
 #include "chrome/browser/ui/blocked_content/popup_blocker_tab_helper.h"
 #include "chrome/browser/ui/blocked_content/tab_under_navigation_throttle.h"
@@ -3202,6 +3203,7 @@ void ChromeContentBrowserClient::OverrideWebkitPrefs(
   }
 #endif  // !defined(OS_ANDROID)
 
+  web_prefs->translate_service_available = TranslateService::IsAvailable(prefs);
   for (size_t i = 0; i < extra_parts_.size(); ++i)
     extra_parts_[i]->OverrideWebkitPrefs(rvh, web_prefs);
 }

chrome/browser/translate/translate_service.cc

@@ -143,3 +143,8 @@ bool TranslateService::IsTranslatableURL(const GURL& url) {
 #endif
          !url.SchemeIs(url::kFtpScheme);
 }
+
+bool TranslateService::IsAvailable(PrefService* prefs) {
+  return translate::TranslateManager::IsAvailable(
+      ChromeTranslateClient::CreateTranslatePrefs(prefs).get());
+}

chrome/browser/translate/translate_service.h

@@ -44,6 +44,9 @@ class TranslateService
   // Returns true if the URL can be translated.
   static bool IsTranslatableURL(const GURL& url);
 
+  // Returns true if the service is available and enabled by user preferences.
+  static bool IsAvailable(PrefService* prefs);
+
  private:
   TranslateService();
   ~TranslateService() override;

components/translate/core/browser/translate_manager.cc

@@ -558,6 +558,15 @@ void TranslateManager::SetIgnoreMissingKeyForTesting(bool ignore) {
   ignore_missing_key_for_testing_ = ignore;
 }
 
+// static
+bool TranslateManager::IsAvailable(const TranslatePrefs* prefs) {
+  // These conditions mirror the conditions in InitiateTranslation.
+  return base::FeatureList::IsEnabled(translate::kTranslateUI) &&
+         (ignore_missing_key_for_testing_ ||
+          ::google_apis::HasAPIKeyConfigured()) &&
+         prefs->IsOfferTranslateEnabled();
+}
+
 void TranslateManager::InitTranslateEvent(const std::string& src_lang,
                                           const std::string& dst_lang,
                                           const TranslatePrefs& prefs) {

components/translate/core/browser/translate_manager.h

@@ -140,6 +140,12 @@ class TranslateManager {
   // testing, set to true to offer anyway.
   static void SetIgnoreMissingKeyForTesting(bool ignore);
 
+  // Returns true if the TranslateManager is available and enabled by user
+  // preferences. It is not available for builds without API keys.
+  // blink's hrefTranslate attribute existence relies on the result.
+  // See https://github.com/dtapuska/html-translate
+  static bool IsAvailable(const TranslatePrefs* prefs);
+
   // Returns true if the decision should be overridden and logs the event
   // appropriately. |event_type| must be one of the
   // values defined by metrics::TranslateEventProto::EventType.

content/public/common/common_param_traits_macros.h

@@ -239,6 +239,7 @@ IPC_STRUCT_TRAITS_BEGIN(content::WebPreferences)
   IPC_STRUCT_TRAITS_MEMBER(autoplay_policy)
   IPC_STRUCT_TRAITS_MEMBER(low_priority_iframes_threshold)
   IPC_STRUCT_TRAITS_MEMBER(picture_in_picture_enabled)
+  IPC_STRUCT_TRAITS_MEMBER(translate_service_available)
   IPC_STRUCT_TRAITS_MEMBER(lazy_frame_loading_distance_thresholds_px)
 IPC_STRUCT_TRAITS_END()
 

content/public/common/web_preferences.cc

@@ -236,7 +236,8 @@ WebPreferences::WebPreferences()
       do_not_update_selection_on_mutating_selection_range(false),
       autoplay_policy(AutoplayPolicy::kDocumentUserActivationRequired),
       low_priority_iframes_threshold(net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN),
-      picture_in_picture_enabled(true) {
+      picture_in_picture_enabled(true),
+      translate_service_available(false) {
   standard_font_family_map[kCommonScript] =
       base::ASCIIToUTF16("Times New Roman");
   fixed_font_family_map[kCommonScript] = base::ASCIIToUTF16("Courier New");

content/public/common/web_preferences.h

@@ -306,6 +306,11 @@ struct CONTENT_EXPORT WebPreferences {
   // Whether Picture-in-Picture is enabled.
   bool picture_in_picture_enabled;
 
+  // Whether a translate service is available.
+  // blink's hrefTranslate attribute existence relies on the result.
+  // See https://github.com/dtapuska/html-translate
+  bool translate_service_available;
+
   // Specifies how close a lazily loaded iframe or image should be from the
   // viewport before it should start being loaded in, depending on the effective
   // connection type of the current network. Blink will use the default distance

content/renderer/render_view_impl.cc

@@ -997,6 +997,13 @@ void RenderView::ApplyWebPreferences(const WebPreferences& prefs,
 #if defined(OS_WIN)
   WebRuntimeFeatures::EnableMiddleClickAutoscroll(true);
 #endif
+
+  // Only enable href translate if we have the experimental web platform
+  // flag on and the translation service is available.
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableExperimentalWebPlatformFeatures)) {
+    WebRuntimeFeatures::EnableHrefTranslate(prefs.translate_service_available);
+  }
 }
 
 /*static*/

content/shell/renderer/layout_test/blink_test_helpers.cc

@@ -145,6 +145,7 @@ void ApplyLayoutTestDefaultPreferences(WebPreferences* prefs) {
   prefs->default_maximum_page_scale_factor = 4.f;
   prefs->presentation_receiver =
       command_line.HasSwitch(switches::kForcePresentationReceiverForTesting);
+  prefs->translate_service_available = true;
 }
 
 base::FilePath GetWebKitRootDirFilePath() {

third_party/WebKit/LayoutTests/webexposed/element-instance-property-listing-expected.txt

@@ -308,6 +308,7 @@ html element a
     property host
     property hostname
     property href
+    property hrefTranslate
     property hreflang
     property name
     property origin

third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt

@@ -2254,6 +2254,7 @@ interface HTMLAnchorElement : HTMLElement
     getter host
     getter hostname
     getter href
+    getter hrefTranslate
     getter hreflang
     getter name
     getter origin
@@ -2281,6 +2282,7 @@ interface HTMLAnchorElement : HTMLElement
     setter host
     setter hostname
     setter href
+    setter hrefTranslate
     setter hreflang
     setter name
     setter password

third_party/blink/public/platform/web_runtime_features.h

@@ -203,6 +203,7 @@ class WebRuntimeFeatures {
       bool);
   BLINK_PLATFORM_EXPORT static void EnableAutoplayIgnoresWebAudio(bool);
   BLINK_PLATFORM_EXPORT static void EnableMediaControlsExpandGesture(bool);
+  BLINK_PLATFORM_EXPORT static void EnableHrefTranslate(bool);
 
  private:
   WebRuntimeFeatures();

third_party/blink/renderer/core/html/html_anchor_element.cc

@@ -397,6 +397,7 @@ void HTMLAnchorElement::HandleClick(Event& event) {
   }
   if (HasRel(kRelationNoOpener))
     frame_request.SetShouldSetOpener(kNeverSetOpener);
+  frame_request.SetHrefTranslate(FastGetAttribute(hreftranslateAttr));
   frame_request.SetTriggeringEventInfo(
       event.isTrusted() ? WebTriggeringEventInfo::kFromTrustedEvent
                         : WebTriggeringEventInfo::kFromUntrustedEvent);

third_party/blink/renderer/core/html/html_anchor_element.idl

@@ -27,6 +27,7 @@ interface HTMLAnchorElement : HTMLElement {
     [CEReactions, Reflect] attribute DOMString rel;
     [SameObject, PutForwards=value] readonly attribute DOMTokenList relList;
     [CEReactions, Reflect] attribute DOMString hreflang;
+    [RuntimeEnabled=HrefTranslate, CEReactions, Reflect] attribute DOMString hrefTranslate;
     [CEReactions, Reflect] attribute DOMString type;
     [CEReactions, Reflect, ReflectOnly=("","no-referrer","origin","no-referrer-when-downgrade","origin-when-cross-origin","unsafe-url"), ReflectMissing="", ReflectInvalid=""] attribute DOMString referrerPolicy;
 

third_party/blink/renderer/core/html/html_attribute_names.json5

@@ -92,6 +92,7 @@
     "high",
     "href",
     "hreflang",
+    "hreftranslate",
     "hspace",
     "http-equiv",
     "id",

third_party/blink/renderer/core/loader/frame_load_request.h

@@ -109,6 +109,11 @@ struct CORE_EXPORT FrameLoadRequest {
     should_set_opener_ = should_set_opener;
   }
 
+  const AtomicString& HrefTranslate() { return href_translate_; }
+  void SetHrefTranslate(const AtomicString& translate) {
+    href_translate_ = translate;
+  }
+
   ContentSecurityPolicyDisposition ShouldCheckMainWorldContentSecurityPolicy()
       const {
     return should_check_main_world_content_security_policy_;
@@ -160,6 +165,7 @@ struct CORE_EXPORT FrameLoadRequest {
   Member<Document> origin_document_;
   ResourceRequest resource_request_;
   AtomicString frame_name_;
+  AtomicString href_translate_;
   SubstituteData substitute_data_;
   bool replaces_current_item_;
   ClientRedirectPolicy client_redirect_;

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -568,4 +568,8 @@ void WebRuntimeFeatures::EnableMediaControlsExpandGesture(bool enable) {
   RuntimeEnabledFeatures::SetMediaControlsExpandGestureEnabled(enable);
 }
 
+void WebRuntimeFeatures::EnableHrefTranslate(bool enable) {
+  RuntimeEnabledFeatures::SetHrefTranslateEnabled(enable);
+}
+
 }  // namespace blink

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -540,6 +540,11 @@
     {
       name: "HeapUnifiedGarbageCollection",
     },
+    // Only exposed when a translation engine is available
+    // and experimental features are enabled.
+    {
+      name: "HrefTranslate",
+    },
     // https://crbug.com/766694 for testing disabling the feature.
     {
       name: "HTMLImports",