Integrate About page into Settings for Chrome OS settings in a window.

ui/webui/resources/js/cr/ui/page_manager/page_manager.js

Index: ui/webui/resources/js/cr/ui/page_manager/page_manager.js
diff --git a/ui/webui/resources/js/cr/ui/page_manager/page_manager.js b/ui/webui/resources/js/cr/ui/page_manager/page_manager.js
index 6f9f1cce3ffe6bd8bccb1c84cb3e3a46d359816e..e312b909f7aa0e0f11b76d6342289a4a4712c50a 100644
--- a/ui/webui/resources/js/cr/ui/page_manager/page_manager.js
+++ b/ui/webui/resources/js/cr/ui/page_manager/page_manager.js
@@ -193,7 +193,7 @@ cr.define('cr.ui.pageManager', function() {
                    this.registeredOverlayPages[name];
         if (!page.parentPage && isRootPageLocked)
           continue;
-        if (page.willHidePage && name != pageName &&
+        if (page.visible && name != pageName &&

[Dan Beam, 2014/08/13 02:50:46]

why did you add this visibility check?

[michaelpg, 2014/08/13 08:12:11]

because this doesn't match the comment: "notify pages if they will be hidden",
not "notify pages if they will be hidden or if they are already hidden". this
leads to workarounds where implementers have to check if the page is actually
visible, e.g.:

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/res...

i think this was also related to adding the willHidePage function that other
classes were "overriding", but I don't really remember how anymore. i'll leave
it out of this CL.

             !this.isAncestorOfPage(page, targetPage)) {
           page.willHidePage();
         }
@@ -228,7 +228,7 @@ cr.define('cr.ui.pageManager', function() {
                    this.registeredOverlayPages[name];
         if (!page.parentPage && isRootPageLocked)
           continue;
-        if (!targetPageWasVisible && page.didShowPage &&
+        if (!targetPageWasVisible &&
             (name == pageName || this.isAncestorOfPage(page, targetPage))) {
           page.didShowPage();
         }
@@ -305,8 +305,9 @@ cr.define('cr.ui.pageManager', function() {
     onPageVisibilityChanged: function(page) {
       this.updateRootPageFreezeState();
 
-      for (var i = 0; i < this.observers_.length; ++i)
+      for (var i = 0; i < this.observers_.length; ++i) {
         this.observers_[i].onPageVisibilityChanged(page);
+      }
 
       if (!page.visible && this.isTopLevelOverlay(page))
         this.updateScrollPosition_();
@@ -332,9 +333,8 @@ cr.define('cr.ui.pageManager', function() {
         return;
 
       overlay.visible = false;
+      overlay.didClosePage();
 
-      if (overlay.didClosePage)
-        overlay.didClosePage();
       this.updateHistoryState_(false, {ignoreHash: true});
       this.updateTitle_();
 
@@ -420,7 +420,7 @@ cr.define('cr.ui.pageManager', function() {
                     this.defaultPage_;
       if (currentOverlay && !this.isAncestorOfPage(currentOverlay, newPage)) {
         currentOverlay.visible = false;
-        if (currentOverlay.didClosePage) currentOverlay.didClosePage();
+        currentOverlay.didClosePage();
       }
       this.showPageByName(pageName, false);
     },
@@ -440,7 +440,7 @@ cr.define('cr.ui.pageManager', function() {
      */
     willClose: function() {
       var overlay = this.getVisibleOverlay_();
-      if (overlay && overlay.didClosePage)
+      if (overlay)
         overlay.didClosePage();
     },
 
@@ -495,8 +495,7 @@ cr.define('cr.ui.pageManager', function() {
 
       if (!overlay.visible) {
         overlay.visible = true;
-        if (overlay.didShowPage)
-          overlay.didShowPage();
+        overlay.didShowPage();
       }
 
       // Change focus to the overlay if any other control was focused by