Fix several crashes for ARC app launcher.

chrome/browser/ui/app_list/arc/arc_app_item.cc

Index: chrome/browser/ui/app_list/arc/arc_app_item.cc
diff --git a/chrome/browser/ui/app_list/arc/arc_app_item.cc b/chrome/browser/ui/app_list/arc/arc_app_item.cc
index 2e1a312772dc77c5408d562880f36fa72fe8eb8b..225ac4b1397249b1a3cb10013e6d186f089a18a3 100644
--- a/chrome/browser/ui/app_list/arc/arc_app_item.cc
+++ b/chrome/browser/ui/app_list/arc/arc_app_item.cc
@@ -73,7 +73,10 @@ const char* ArcAppItem::GetItemType() const {
 }
 
 void ArcAppItem::Activate(int event_flags) {
-  DCHECK(ready_);
+  if (!ready()) {

[khmel, 2015/12/08 05:42:51]

Ready is our internal sate only and Activate may be called for not-ready apps.
Handle this case correctly.

+    VLOG(2) << "Cannot launch not-ready app:" << id() << ".";
+    return;
+  }
 
   ArcAppListPrefs* prefs = ArcAppListPrefs::Get(context_);
   scoped_ptr<ArcAppListPrefs::AppInfo> app_info = prefs->GetApp(id());