[Media Router] Assign each route a current cast mode if possible

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

Index: chrome/browser/resources/media_router/elements/media_router_container/media_router_container.js
diff --git a/chrome/browser/resources/media_router/elements/media_router_container/media_router_container.js b/chrome/browser/resources/media_router/elements/media_router_container/media_router_container.js
index d58a5ac8286a0b1555746cb36be4af4afd094faa..7309fd874dc634947c872e15696e0ef991c1d6f8 100644
--- a/chrome/browser/resources/media_router/elements/media_router_container/media_router_container.js
+++ b/chrome/browser/resources/media_router/elements/media_router_container/media_router_container.js
@@ -707,6 +707,18 @@ Polymer({
   },
 
   /**
+   * @param {?Element} element Element to compute padding for.
+   * @return {number} Computes the amount of vertical padding (top + bottom) on
+   *     |element|.
+   * @private
+   */
+  computeElementVerticalPadding_: function(element) {
+    var paddingBottom, paddingTop;
+    [paddingBottom, paddingTop] = this.getElementVerticalPadding_(element);
+    return paddingBottom + paddingTop;
+  },
+
+  /**
    * @param {?media_router.MediaRouterView} view The current view.
    * @param {?media_router.Issue} issue The current issue.
    * @return {boolean} Whether or not to hide the header.
@@ -809,6 +821,38 @@ Polymer({
   },
 
   /**
+   * @param {?media_router.Route|undefined} currentRoute The current route for
+   *     the route details view.
+   * @param {string} currentLaunchingSinkId ID of the currently launching sink
+   *     or the empty string if no sink is launching.
+   * @param {number} shownCastModeValue Currently selected cast mode value or
+   *     AUTO if no value has been explicitly selected.
+   * @return {boolean} Whether the replace route function should be available
+   *     when displaying |currentRoute| in the route details view. Replace route
+   *     should not be available when the source that would be cast from when
+   *     creating a new route would be the same as the route's current source.
+   * @private
+   */
+  computeReplaceRouteAvailable_: function(
+      currentRoute, currentLaunchingSinkId, shownCastModeValue) {
+    if (currentLaunchingSinkId || !currentRoute) {
+      return false;
+    }
+    if (!currentRoute.currentCastMode) {
+      return true;
+    }
+    var selectedCastMode = shownCastModeValue;
+    if (selectedCastMode == media_router.CastModeType.AUTO) {
+      var sink = this.sinkMap_[currentRoute.sinkId];
+      if (!sink) {
+        return false;
+      }
+      selectedCastMode = sink.castModes & -sink.castModes;
+    }
+    return selectedCastMode != currentRoute.currentCastMode;
+  },
+
+  /**
    * @param {?media_router.MediaRouterView} view The current view.
    * @param {?media_router.Issue} issue The current issue.
    * @return {boolean} Whether or not to hide the route details.
@@ -820,18 +864,6 @@ Polymer({
   },
 
   /**
-   * @param {?Element} element Element to compute padding for.
-   * @return {number} Computes the amount of vertical padding (top + bottom) on
-   *     |element|.
-   * @private
-   */
-  computeElementVerticalPadding_: function(element) {
-    var paddingBottom, paddingTop;
-    [paddingBottom, paddingTop] = this.getElementVerticalPadding_(element);
-    return paddingBottom + paddingTop;
-  },
-
-  /**
    * Computes an array of substring indices that mark where substrings of
    * |searchString| occur in |sinkName|.
    *