Adding Discarded property support for onUpdate function.

chrome/browser/extensions/api/tabs/tabs_event_router.cc

Index: chrome/browser/extensions/api/tabs/tabs_event_router.cc
diff --git a/chrome/browser/extensions/api/tabs/tabs_event_router.cc b/chrome/browser/extensions/api/tabs/tabs_event_router.cc
index 80c495c96736c1de6aa06d668eb52bdbe8adad82..3a2f021973e711d9e30cab67ce2e591e407a7dd8 100644
--- a/chrome/browser/extensions/api/tabs/tabs_event_router.cc
+++ b/chrome/browser/extensions/api/tabs/tabs_event_router.cc
@@ -11,10 +11,12 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
 #include "chrome/browser/extensions/api/tabs/tabs_windows_api.h"
 #include "chrome/browser/extensions/api/tabs/windows_event_router.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
+#include "chrome/browser/memory/tab_manager.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
@@ -135,11 +137,14 @@ void TabsEventRouter::TabEntry::WebContentsDestroyed() {
 TabsEventRouter::TabsEventRouter(Profile* profile)
     : profile_(profile),
       favicon_scoped_observer_(this),
-      browser_tab_strip_tracker_(this, this, this) {
+      browser_tab_strip_tracker_(this, this, this),
+      tab_manager_scoped_observer_(this) {
   DCHECK(!profile->IsOffTheRecord());
 
   browser_tab_strip_tracker_.Init(
       BrowserTabStripTracker::InitWith::ALL_BROWERS);
+
+  tab_manager_scoped_observer_.Add(g_browser_process->GetTabManager());
 }
 
 TabsEventRouter::~TabsEventRouter() {
@@ -552,4 +557,16 @@ void TabsEventRouter::OnFaviconUpdated(
   }
 }
 
+void TabsEventRouter::OnDiscardedStateChange(WebContents* contents,
+                                             bool is_discarded) {
+  TabStripModel* tab_strip = nullptr;
+  int tab_index = -1;
+
+  if (ExtensionTabUtil::GetTabStripModel(contents, &tab_strip, &tab_index)) {
+    std::set<std::string> changed_property_names;
+    changed_property_names.insert(tabs_constants::kDiscardedKey);
+    DispatchTabUpdatedEvent(contents, std::move(changed_property_names));
+  }
+}
+
 }  // namespace extensions