[Media Router] Add Issues handling in WebUI Message Handler.

This patch consists of:
- new string resources for Issues action button labels.
- convert IssuesObserver from interface to a base class to be consistent
with Media{Sinks,Routes}Observer classes.
- rename {Add,Remove}IssuesObserver to [Un]RegisterIssuesObserver.
- add initiator WebContents field to MediaRouterUI. Note that this will
be set to a non-null value during InitCommon() (crrev.com/1156373014).
- add Issue handling (OnActOnIssue) in WebUI MessageHandler. For the
"Learn more" action, open a Chromecast help page with the supplied page
ID (which comes from WebUI).
- various cleanup/renaming of the function names in WebUI/C++ interfaces
for consistency.

BUG=464216

Review URL: https://codereview.chromium.org/1161113003

Cr-Commit-Position: refs/heads/master@{#334713}

20 files changed, 299 insertions, 22 deletions

diff --git a/chrome/app/media_router_strings.grdp b/chrome/app/media_router_strings.grdp
index cfe94d1..48ed0ab 100644
--- a/chrome/app/media_router_strings.grdp
+++ b/chrome/app/media_router_strings.grdp
@@ -37,6 +37,20 @@
    Select cast mode
   </message>
 
+  <!-- Issue Actions -->
+  <message name="IDS_MEDIA_ROUTER_CANCEL_BUTTON" desc="Text of Cancel button.">
+    Cancel
+  </message>
+  <message name="IDS_MEDIA_ROUTER_DISMISS_BUTTON" desc="Text of Dismiss button.">
+    Dismiss
+  </message>
+  <message name="IDS_MEDIA_ROUTER_LEARN_MORE_BUTTON" desc="Text of Learn More button.">
+    Learn More
+  </message>
+  <message name="IDS_MEDIA_ROUTER_OK_BUTTON" desc="Text of Ok button.">
+    Ok
+  </message>
+
   <!-- Route Details -->
   <message name="IDS_MEDIA_ROUTER_BACK_TO_SINK_PICKER" desc="Label of back to sink picker button.">
     Back to device list
diff --git a/chrome/browser/media/router/issues_observer.cc b/chrome/browser/media/router/issues_observer.cc
new file mode 100644
index 0000000..0d496d8
--- /dev/null
+++ b/chrome/browser/media/router/issues_observer.cc
@@ -0,0 +1,21 @@
+// Copyright 2015 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 "chrome/browser/media/router/issues_observer.h"
+
+#include "base/logging.h"
+#include "chrome/browser/media/router/media_router.h"
+
+namespace media_router {
+
+IssuesObserver::IssuesObserver(MediaRouter* router) : router_(router) {
+  DCHECK(router_);
+  router_->RegisterIssuesObserver(this);
+}
+
+IssuesObserver::~IssuesObserver() {
+  router_->UnregisterIssuesObserver(this);
+}
+
+}  // namespace media_router
diff --git a/chrome/browser/media/router/issues_observer.h b/chrome/browser/media/router/issues_observer.h
index 33443dd..d8b4258 100644
--- a/chrome/browser/media/router/issues_observer.h
+++ b/chrome/browser/media/router/issues_observer.h
@@ -9,15 +9,23 @@
 
 namespace media_router {
 
-// Interface for observing when issues have been updated.
-// TODO(imcheng): Implement automatic register/unregister from MediaRouter.
+class MediaRouter;
+
+// Base class for observing Media Router Issue. There is at most one Issue
+// at any given time.
 class IssuesObserver {
  public:
-  virtual ~IssuesObserver() {}
+  explicit IssuesObserver(MediaRouter* router);
+  virtual ~IssuesObserver();
+
+  // Called when there is an updated Media Router Issue.
+  // If |issue| is nullptr, then there is currently no issue.
+  virtual void OnIssueUpdated(const Issue* issue) {}
+
+ private:
+  MediaRouter* router_;
 
-  // Called when there is a new highest priority issue.
-  // |issue| can be nullptr.
-  virtual void OnIssueUpdated(const Issue* issue) = 0;
+  DISALLOW_COPY_AND_ASSIGN(IssuesObserver);
 };
 
 }  // namespace media_router
diff --git a/chrome/browser/media/router/media_router.gypi b/chrome/browser/media/router/media_router.gypi
index 4851a43..460c38e 100644
--- a/chrome/browser/media/router/media_router.gypi
+++ b/chrome/browser/media/router/media_router.gypi
@@ -13,6 +13,7 @@
       'issue_manager.cc',
       'issue_manager.h',
       'issues_observer.h',
+      'issues_observer.cc',
       'media_route.cc',
       'media_route.h',
       'media_route_id.h',
diff --git a/chrome/browser/media/router/media_router.h b/chrome/browser/media/router/media_router.h
index 3280798..071f55b 100644
--- a/chrome/browser/media/router/media_router.h
+++ b/chrome/browser/media/router/media_router.h
@@ -132,10 +132,10 @@ class MediaRouter {
   // Adds the IssuesObserver |observer|.
   // It is invalid to register the same observer more than once and will result
   // in undefined behavior.
-  virtual void AddIssuesObserver(IssuesObserver* observer) = 0;
+  virtual void RegisterIssuesObserver(IssuesObserver* observer) = 0;
 
   // Removes the IssuesObserver |observer|.
-  virtual void RemoveIssuesObserver(IssuesObserver* observer) = 0;
+  virtual void UnregisterIssuesObserver(IssuesObserver* observer) = 0;
 };
 
 }  // namespace media_router
diff --git a/chrome/browser/media/router/media_router_mojo_impl.cc b/chrome/browser/media/router/media_router_mojo_impl.cc
index 0528a9f..d8c81e8 100644
--- a/chrome/browser/media/router/media_router_mojo_impl.cc
+++ b/chrome/browser/media/router/media_router_mojo_impl.cc
@@ -285,12 +285,12 @@ void MediaRouterMojoImpl::UnregisterMediaRoutesObserver(
   }
 }
 
-void MediaRouterMojoImpl::AddIssuesObserver(IssuesObserver* observer) {
+void MediaRouterMojoImpl::RegisterIssuesObserver(IssuesObserver* observer) {
   // TODO(imcheng): Implement. (crbug.com/461815)
   NOTIMPLEMENTED();
 }
 
-void MediaRouterMojoImpl::RemoveIssuesObserver(IssuesObserver* observer) {
+void MediaRouterMojoImpl::UnregisterIssuesObserver(IssuesObserver* observer) {
   // TODO(imcheng): Implement. (crbug.com/461815)
   NOTIMPLEMENTED();
 }
diff --git a/chrome/browser/media/router/media_router_mojo_impl.h b/chrome/browser/media/router/media_router_mojo_impl.h
index febd0d5..a1be573 100644
--- a/chrome/browser/media/router/media_router_mojo_impl.h
+++ b/chrome/browser/media/router/media_router_mojo_impl.h
@@ -78,8 +78,8 @@ class MediaRouterMojoImpl : public MediaRouter,
   void UnregisterMediaSinksObserver(MediaSinksObserver* observer) override;
   void RegisterMediaRoutesObserver(MediaRoutesObserver* observer) override;
   void UnregisterMediaRoutesObserver(MediaRoutesObserver* observer) override;
-  void AddIssuesObserver(IssuesObserver* observer) override;
-  void RemoveIssuesObserver(IssuesObserver* observer) override;
+  void RegisterIssuesObserver(IssuesObserver* observer) override;
+  void UnregisterIssuesObserver(IssuesObserver* observer) override;
 
   void set_instance_id_for_test(const std::string& instance_id) {
     instance_id_ = instance_id;
diff --git a/chrome/browser/media/router/mock_media_router.h b/chrome/browser/media/router/mock_media_router.h
index 74cdb70..8eadf62 100644
--- a/chrome/browser/media/router/mock_media_router.h
+++ b/chrome/browser/media/router/mock_media_router.h
@@ -41,8 +41,8 @@ class MockMediaRouter : public MediaRouter {
                     const std::string& message,
                     const SendRouteMessageCallback& callback));
   MOCK_METHOD1(ClearIssue, void(const Issue::Id& issue_id));
-  MOCK_METHOD1(AddIssuesObserver, void(IssuesObserver* observer));
-  MOCK_METHOD1(RemoveIssuesObserver, void(IssuesObserver* observer));
+  MOCK_METHOD1(RegisterIssuesObserver, void(IssuesObserver* observer));
+  MOCK_METHOD1(UnregisterIssuesObserver, void(IssuesObserver* observer));
 
   MOCK_METHOD1(RegisterMediaSinksObserver, void(MediaSinksObserver* observer));
   MOCK_METHOD1(UnregisterMediaSinksObserver,
diff --git a/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.html b/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.html
index bdc2ae3..835f83f 100644
--- a/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.html
+++ b/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.html
@@ -19,7 +19,7 @@
         </paper-button>
         <paper-button raised class="button action"
             on-click="onClickDefaultAction_">
-          <span>[[issue.defaultActionText]]</span>
+          <span>[[defaultActionButtonText_]]</span>
         </paper-button>
       </div>
     </div>
@@ -34,7 +34,7 @@
         <span>[[issue.optActionText]]</span>
       </span>
       <span class="issue-action" on-click="onClickDefaultAction_">
-        <span>[[issue.defaultActionText]]</span>
+        <span>[[defaultActionButtonText_]]</span>
       </span>
     </div>
   </template>
diff --git a/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.js b/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.js
index 9cde810..ec1ded8 100644
--- a/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.js
+++ b/chrome/browser/resources/media_router/elements/issue_banner/issue_banner.js
@@ -4,6 +4,16 @@
 
 // This Polymer element is used to show information about issues related
 // to casting.
+(function() {
+
+/**
+ * Maps an issue action type to the resource identifier of the text shown
+ * in the action button.
+ * @type {!Array<string>}
+ */
+var issueActionTypeToButtonTextResource = [
+    'okButton', 'cancelButton', 'dismissButton', 'learnMoreButton'];
+
 Polymer({
   is: 'issue-banner',
 
@@ -16,6 +26,18 @@ Polymer({
       type: Object,
       value: null,
     },
+
+    /**
+     * The text shown in the default action button.
+     * @private {string}
+     */
+    defaultActionButtonText_: {
+      type: String,
+      value: function() {
+        return loadTimeData.getString(
+            issueActionTypeToButtonTextResource[issue.defaultActionType]);
+      },
+    },
   },
 
   /**
@@ -56,7 +78,7 @@ Polymer({
     this.fire('issue-action-click', {
       id: this.issue.id,
       actionType: actionType,
-      helpPageId: this.issue.helpPageId,
+      helpPageId: this.issue.helpPageId
     });
   },
 
@@ -80,3 +102,4 @@ Polymer({
     this.fireIssueActionClick_(this.issue.optActionType);
   },
 });
+})();
diff --git a/chrome/browser/resources/media_router/media_router.js b/chrome/browser/resources/media_router/media_router.js
index f567ce2..4773a16 100644
--- a/chrome/browser/resources/media_router/media_router.js
+++ b/chrome/browser/resources/media_router/media_router.js
@@ -40,7 +40,8 @@ cr.define('media_router', function() {
    * Acts on an issue and dismisses it from the UI.
    * Called when the user performs an action on an issue.
    *
-   * @param {{detail: {id: string, actionType: number}}} data
+   * @param {{detail: {id: string, actionType: number, helpPageId: number}}}
+   *     data
    * Parameters in |data|.detail:
    *   id - issue ID.
    *   actionType - type of action performed by the user.
diff --git a/chrome/browser/resources/media_router/media_router_ui_interface.js b/chrome/browser/resources/media_router/media_router_ui_interface.js
index f9437116..aa8680e 100644
--- a/chrome/browser/resources/media_router/media_router_ui_interface.js
+++ b/chrome/browser/resources/media_router/media_router_ui_interface.js
@@ -11,6 +11,26 @@ cr.define('media_router.ui', function() {
   var container = null;
 
   /**
+   * Populates the WebUI with data obtained from Media Router.
+   *
+   * @param {{headerText: string,
+   *          sinks: !Array<!media_router.Sink>,
+   *          routes: !Array<!media_router.Route>,
+   *          castModes: !Array<!media_router.CastMode>}} data
+   * Parameters in data:
+   *   headerText - text to be displayed in the header of the WebUI.
+   *   sinks - list of sinks to be displayed.
+   *   routes - list of routes that are associated with the sinks.
+   *   castModes - list of available cast modes.
+   */
+  function setInitialData(data) {
+    container.headerText = data['headerText'];
+    container.sinkList = data['sinks'];
+    container.routeList = data['routes'];
+    container.castModeList = data['castModes'];
+  }
+
+  /**
    * Adds a new route.
    *
    * @param {!media_router.Route} route
diff --git a/chrome/browser/ui/webui/media_router/media_cast_mode.h b/chrome/browser/ui/webui/media_router/media_cast_mode.h
index 7c9e069..80af5d4 100644
--- a/chrome/browser/ui/webui/media_router/media_cast_mode.h
+++ b/chrome/browser/ui/webui/media_router/media_cast_mode.h
@@ -32,6 +32,7 @@ enum MediaCastMode {
 
 using CastModeSet = std::set<MediaCastMode>;
 
+// TODO(imcheng): Move localization logic to WebUI.
 // Returns a localized title string for |mode| and |host| (e.g. google.com).
 std::string MediaCastModeToTitle(MediaCastMode mode, const std::string& host);
 
diff --git a/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc b/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
index d8693b3..90cdd0f 100644
--- a/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
@@ -28,6 +28,16 @@ void AddRouteDetailsStrings(content::WebUIDataSource* html_source) {
       IDS_MEDIA_ROUTER_STOP_CASTING_BUTTON);
 }
 
+void AddIssuesActionsStrings(content::WebUIDataSource* html_source) {
+  html_source->AddLocalizedString("cancelButton",
+                                  IDS_MEDIA_ROUTER_CANCEL_BUTTON);
+  html_source->AddLocalizedString("dismissButton",
+                                  IDS_MEDIA_ROUTER_DISMISS_BUTTON);
+  html_source->AddLocalizedString("learnMoreButton",
+                                  IDS_MEDIA_ROUTER_LEARN_MORE_BUTTON);
+  html_source->AddLocalizedString("okButton", IDS_MEDIA_ROUTER_OK_BUTTON);
+}
+
 }  // namespace
 
 namespace media_router {
@@ -35,6 +45,7 @@ namespace media_router {
 void AddLocalizedStrings(content::WebUIDataSource* html_source) {
   AddMediaRouterStrings(html_source);
   AddRouteDetailsStrings(html_source);
+  AddIssuesActionsStrings(html_source);
   html_source->SetJsonPath(kLocalizedStringsFile);
 }
 
diff --git a/chrome/browser/ui/webui/media_router/media_router_ui.cc b/chrome/browser/ui/webui/media_router/media_router_ui.cc
index 752c006..2b2b54a 100644
--- a/chrome/browser/ui/webui/media_router/media_router_ui.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_ui.cc
@@ -50,7 +50,10 @@ std::string GetHostFromURL(const GURL& gurl) {
 // updated.
 class MediaRouterUI::UIIssuesObserver : public IssuesObserver {
  public:
-  explicit UIIssuesObserver(MediaRouterUI* ui) : ui_(ui) { DCHECK(ui); }
+  UIIssuesObserver(MediaRouter* router, MediaRouterUI* ui)
+      : IssuesObserver(router), ui_(ui) {
+    DCHECK(ui);
+  }
 
   ~UIIssuesObserver() override {}
 
@@ -151,7 +154,7 @@ void MediaRouterUI::InitCommon(const content::WebContents* initiator,
   DCHECK(initiator);
 
   // Register for Issue and MediaRoute updates.
-  issues_observer_.reset(new UIIssuesObserver(this));
+  issues_observer_.reset(new UIIssuesObserver(router_, this));
   routes_observer_.reset(new UIMediaRoutesObserver(router_, this));
 
   query_result_manager_.reset(new QueryResultManager(router_));
diff --git a/chrome/browser/ui/webui/media_router/media_router_ui.h b/chrome/browser/ui/webui/media_router/media_router_ui.h
index bec84a8..e3e4a21 100644
--- a/chrome/browser/ui/webui/media_router/media_router_ui.h
+++ b/chrome/browser/ui/webui/media_router/media_router_ui.h
@@ -105,7 +105,6 @@ class MediaRouterUI
   const std::vector<MediaSinkWithCastModes>& sinks() const { return sinks_; }
   const std::vector<MediaRoute>& routes() const { return routes_; }
   const std::set<MediaCastMode>& cast_modes() const { return cast_modes_; }
-
   const content::WebContents* initiator() const { return initiator_; }
 
  private:
diff --git a/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.cc b/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.cc
index b27a8c4..03e9eca 100644
--- a/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.cc
@@ -309,7 +309,7 @@ void MediaRouterWebUIMessageHandler::OnCloseRoute(
   const base::DictionaryValue* args_dict = nullptr;
   std::string route_id;
   if (!args->GetDictionary(0, &args_dict) ||
-      !args_dict->GetString(0, &route_id)) {
+      !args_dict->GetString("routeId", &route_id)) {
     DVLOG(1) << "Unable to extract args.";
     return;
   }
diff --git a/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.h b/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.h
index 8193358..0fbfbee 100644
--- a/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.h
+++ b/chrome/browser/ui/webui/media_router/media_router_webui_message_handler.h
@@ -14,6 +14,7 @@
 #include "content/public/browser/web_ui_message_handler.h"
 
 namespace base {
+class DictionaryValue;
 class ListValue;
 }  // namespace base
 
diff --git a/chrome/browser/ui/webui/media_router/media_router_webui_message_handler_unittest.cc b/chrome/browser/ui/webui/media_router/media_router_webui_message_handler_unittest.cc
new file mode 100644
index 0000000..105d0a1
--- /dev/null
+++ b/chrome/browser/ui/webui/media_router/media_router_webui_message_handler_unittest.cc
@@ -0,0 +1,173 @@
+// Copyright 2015 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 "chrome/browser/ui/webui/media_router/media_router_webui_message_handler.h"
+#include "content/public/test/test_web_ui.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media_router {
+
+class TestingMediaRouterWebUIMessageHandler
+    : public MediaRouterWebUIMessageHandler {
+ public:
+  explicit TestingMediaRouterWebUIMessageHandler(content::WebUI* web_ui) {
+    set_web_ui(web_ui);
+  }
+
+  ~TestingMediaRouterWebUIMessageHandler() override { set_web_ui(nullptr); }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestingMediaRouterWebUIMessageHandler);
+};
+
+class MediaRouterWebUIMessageHandlerTest : public testing::Test {
+ public:
+  MediaRouterWebUIMessageHandlerTest() : web_ui_(), handler_(&web_ui_) {}
+  ~MediaRouterWebUIMessageHandlerTest() override {}
+
+ protected:
+  content::TestWebUI web_ui_;
+  TestingMediaRouterWebUIMessageHandler handler_;
+};
+
+TEST_F(MediaRouterWebUIMessageHandlerTest, UpdateSinks) {
+  MediaSink::Id sink_id("sinkId123");
+  std::string sink_name("The sink");
+  std::vector<MediaSinkWithCastModes> media_sink_with_cast_modes_list;
+  MediaSinkWithCastModes media_sink_with_cast_modes(
+      MediaSink(sink_id, sink_name));
+  media_sink_with_cast_modes.cast_modes.insert(MediaCastMode::TAB_MIRROR);
+  media_sink_with_cast_modes_list.push_back(media_sink_with_cast_modes);
+
+  handler_.UpdateSinks(media_sink_with_cast_modes_list);
+  EXPECT_EQ(1u, web_ui_.call_data().size());
+  const content::TestWebUI::CallData& call_data = *web_ui_.call_data()[0];
+  EXPECT_EQ("media_router.ui.setSinkList", call_data.function_name());
+  const base::Value* arg1 = call_data.arg1();
+  const base::ListValue* sinks_list_value = nullptr;
+  EXPECT_TRUE(arg1->GetAsList(&sinks_list_value));
+  const base::DictionaryValue* sink_value = nullptr;
+  EXPECT_TRUE(sinks_list_value->GetDictionary(0, &sink_value));
+
+  std::string value;
+  EXPECT_TRUE(sink_value->GetString("id", &value));
+  EXPECT_EQ(sink_id, value);
+
+  EXPECT_TRUE(sink_value->GetString("name", &value));
+  EXPECT_EQ(sink_name, value);
+
+  const base::ListValue* cast_modes_value = nullptr;
+  EXPECT_TRUE(sink_value->GetList("castModes", &cast_modes_value));
+  int cast_mode = -1;
+  EXPECT_TRUE(cast_modes_value->GetInteger(0, &cast_mode));
+  EXPECT_EQ(static_cast<int>(MediaCastMode::TAB_MIRROR), cast_mode);
+}
+
+TEST_F(MediaRouterWebUIMessageHandlerTest, UpdateRoutes) {
+  MediaRoute::Id route_id("routeId123");
+  MediaSink::Id sink_id("sinkId123");
+  MediaSink sink(sink_id, "The sink");
+  std::string description("This is a route");
+  bool is_local = true;
+  std::vector<MediaRoute> routes;
+  routes.push_back(MediaRoute(route_id, MediaSource("mediaSource"),
+                              MediaSink(sink_id, "The sink"), description,
+                              is_local));
+
+  handler_.UpdateRoutes(routes);
+  EXPECT_EQ(1u, web_ui_.call_data().size());
+  const content::TestWebUI::CallData& call_data = *web_ui_.call_data()[0];
+  EXPECT_EQ("media_router.ui.setRouteList", call_data.function_name());
+  const base::Value* arg1 = call_data.arg1();
+  const base::ListValue* routes_list_value = nullptr;
+  EXPECT_TRUE(arg1->GetAsList(&routes_list_value));
+  const base::DictionaryValue* route_value = nullptr;
+  EXPECT_TRUE(routes_list_value->GetDictionary(0, &route_value));
+
+  std::string value;
+  EXPECT_TRUE(route_value->GetString("id", &value));
+  EXPECT_EQ(route_id, value);
+  EXPECT_TRUE(route_value->GetString("sinkId", &value));
+  EXPECT_EQ(sink_id, value);
+  EXPECT_TRUE(route_value->GetString("title", &value));
+  EXPECT_EQ(description, value);
+
+  bool actual_is_local = false;
+  EXPECT_TRUE(route_value->GetBoolean("isLocal", &actual_is_local));
+  EXPECT_EQ(is_local, actual_is_local);
+}
+
+TEST_F(MediaRouterWebUIMessageHandlerTest, AddRoute) {
+  MediaRoute::Id route_id("routeId123");
+  MediaSink::Id sink_id("sinkId123");
+  MediaSink sink(sink_id, "The sink");
+  std::string description("This is a route");
+  bool is_local = true;
+  MediaRoute route(route_id, MediaSource("mediaSource"),
+                   MediaSink(sink_id, "The sink"), description, is_local);
+
+  handler_.AddRoute(route);
+  EXPECT_EQ(1u, web_ui_.call_data().size());
+  const content::TestWebUI::CallData& call_data = *web_ui_.call_data()[0];
+  EXPECT_EQ("media_router.ui.addRoute", call_data.function_name());
+  const base::Value* arg1 = call_data.arg1();
+  const base::DictionaryValue* route_value = nullptr;
+  EXPECT_TRUE(arg1->GetAsDictionary(&route_value));
+
+  std::string value;
+  EXPECT_TRUE(route_value->GetString("id", &value));
+  EXPECT_EQ(route_id, value);
+  EXPECT_TRUE(route_value->GetString("sinkId", &value));
+  EXPECT_EQ(sink_id, value);
+  EXPECT_TRUE(route_value->GetString("title", &value));
+  EXPECT_EQ(description, value);
+
+  bool actual_is_local = false;
+  EXPECT_TRUE(route_value->GetBoolean("isLocal", &actual_is_local));
+  EXPECT_EQ(is_local, actual_is_local);
+}
+
+TEST_F(MediaRouterWebUIMessageHandlerTest, UpdateIssue) {
+  std::string issue_title("An issue");
+  std::string issue_message("This is an issue");
+  IssueAction default_action(IssueAction::TYPE_OK);
+  std::vector<IssueAction> secondary_actions;
+  secondary_actions.push_back(IssueAction(IssueAction::TYPE_DISMISS));
+  MediaRoute::Id route_id("routeId123");
+  bool is_blocking = true;
+  Issue issue(issue_title, issue_message, default_action, secondary_actions,
+              route_id, Issue::FATAL, is_blocking, "helpUrl");
+  const Issue::Id& issue_id = issue.id();
+
+  handler_.UpdateIssue(&issue);
+  EXPECT_EQ(1u, web_ui_.call_data().size());
+  const content::TestWebUI::CallData& call_data = *web_ui_.call_data()[0];
+  EXPECT_EQ("media_router.ui.setIssue", call_data.function_name());
+  const base::Value* arg1 = call_data.arg1();
+  const base::DictionaryValue* issue_value = nullptr;
+  EXPECT_TRUE(arg1->GetAsDictionary(&issue_value));
+
+  std::string value;
+  EXPECT_TRUE(issue_value->GetString("id", &value));
+  EXPECT_EQ(issue_id, value);
+  EXPECT_TRUE(issue_value->GetString("title", &value));
+  EXPECT_EQ(issue_title, value);
+  EXPECT_TRUE(issue_value->GetString("message", &value));
+  EXPECT_EQ(issue_message, value);
+
+  int action_type_num = -1;
+  EXPECT_TRUE(issue_value->GetInteger("defaultActionType", &action_type_num));
+  EXPECT_EQ(default_action.type(), action_type_num);
+  EXPECT_TRUE(issue_value->GetInteger("secondaryActionType", &action_type_num));
+  EXPECT_EQ(secondary_actions[0].type(), action_type_num);
+
+  EXPECT_TRUE(issue_value->GetString("routeId", &value));
+  EXPECT_EQ(route_id, value);
+
+  bool actual_is_blocking = false;
+  EXPECT_TRUE(issue_value->GetBoolean("isBlocking", &actual_is_blocking));
+  EXPECT_EQ(is_blocking, actual_is_blocking);
+}
+
+}  // namespace media_router
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 9895d64..cfa9dbf 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1456,6 +1456,7 @@
       'browser/ui/webui/media_router/media_router_dialog_controller_unittest.cc',
       'browser/ui/webui/media_router/media_router_test.cc',
       'browser/ui/webui/media_router/media_router_test.h',
+      'browser/ui/webui/media_router/media_router_webui_message_handler_unittest.cc',
       'browser/ui/webui/media_router/query_result_manager_unittest.cc',
     ],
     # Everything but Android and iOS (iOS is handled separately).