[Media Router] Add cloud services learn more link to first run flow.

Part 5.

This change adds a link target to the "Learn More" text in the cloud services pref section of the first run flow. Also reworked some of the HTML/CSS to make the link clickable.

BUG=560457

Review URL: https://codereview.chromium.org/1606303005

Cr-Commit-Position: refs/heads/master@{#371426}

chrome/browser/resources/media_router/elements/media_router_container/media_router_container.css

@@ -73,6 +73,16 @@
   z-index: 1;
 }
 
+#first-run-flow-cloud-pref {
+  color: white;
+  display: flex;
+}
+
+#first-run-flow-cloud-pref a {
+  color: white;
+  text-decoration: none;
+}
+
 #first-run-learn-more {
   font-weight: bold;
   text-transform: uppercase;

chrome/browser/resources/media_router/elements/media_router_container/media_router_container.html

@@ -22,12 +22,18 @@
         <div id="first-run-text">[[firstRunFlowText_]]</div>
         <template is="dom-if" if="[[showFirstRunFlowCloudPref]]">
           <div id="first-run-flow-cloud-pref">
-            <paper-checkbox checked id="first-run-cloud-checkbox">
+            <div>
+              <paper-checkbox checked id="first-run-cloud-checkbox">
+              </paper-checkbox>
+            </div>
+            <div>
               <span>[[firstRunFlowCloudPrefText_]]</span>
-              <span id="first-run-learn-more">
-                [[firstRunFlowCloudLearnMore_]]
-              </span>
-            </paper-checkbox>
+              <a href="[[firstRunFlowCloudPrefLearnMoreUrl]]">
+                <span id="first-run-learn-more">
+                  [[firstRunFlowCloudLearnMore_]]
+                </span>
+              </a>
+            </div>
           </div>
         </template>
         <div id="first-run-button-container">

chrome/browser/resources/media_router/elements/media_router_container/media_router_container.js

@@ -118,6 +118,15 @@ Polymer({
           loadTimeData.getString('firstRunFlowCloudLearnMore') : '',
     },
 
+    /**
+     * The URL to open when the cloud services pref learn more link is clicked.
+     * @type {string}
+     */
+    firstRunFlowCloudPrefLearnMoreUrl: {
+      type: String,
+      value: '',
+    },
+
     /**
      * The text for the cloud services preference description in the first run
      * flow.

chrome/browser/resources/media_router/media_router_ui_interface.js

@@ -50,12 +50,15 @@ cr.define('media_router.ui', function() {
   /**
    * Populates the WebUI with data obtained from Media Router.
    *
-   * @param {{deviceMissingUrl: string,
+   * @param {{firstRunFlowCloudPrefLearnMoreUrl: string,
+   *          deviceMissingUrl: string,
    *          sinks: !Array<!media_router.Sink>,
    *          routes: !Array<!media_router.Route>,
    *          castModes: !Array<!media_router.CastMode>,
    *          wasFirstRunFlowAcknowledged: boolean}} data
    * Parameters in data:
+   *   firstRunFlowCloudPrefLearnMoreUrl - url to open when the cloud services
+   *       pref learn more link is clicked.
    *   deviceMissingUrl - url to be opened on "Device missing?" clicked.
    *   sinks - list of sinks to be displayed.
    *   routes - list of routes that are associated with the sinks.
@@ -64,6 +67,8 @@ cr.define('media_router.ui', function() {
    *       acknowledged by user.
    */
   function setInitialData(data) {
+    container.firstRunFlowCloudPrefLearnMoreUrl =
+        data['firstRunFlowCloudPrefLearnMoreUrl'];
     container.deviceMissingUrl = data['deviceMissingUrl'];
     container.castModeList = data['castModes'];
     container.allSinks = data['sinks'];

chrome/browser/ui/webui/media_router/media_router_webui_message_handler.cc

@@ -325,6 +325,11 @@ void MediaRouterWebUIMessageHandler::OnRequestInitialData(
   media_router_ui_->OnUIInitiallyLoaded();
   base::DictionaryValue initial_data;
 
+#if defined(GOOGLE_CHROME_BUILD)
+  // "Casting to a Hangout from Chrome" Chromecast help center page.
+  initial_data.SetString("firstRunFlowCloudPrefLearnMoreUrl",
+      base::StringPrintf(kHelpPageUrlPrefix, 6320939));
+#endif  // defined(GOOGLE_CHROME_BUILD)
   // "No Cast devices found?" Chromecast help center page.
   initial_data.SetString("deviceMissingUrl",
       base::StringPrintf(kHelpPageUrlPrefix, 3249268));