[blimp] Add support for having multiple tabs

blimp/client/core/contents/navigation_feature.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "blimp/client/core/contents/navigation_feature.h"
 
 #include <map>
 #include <string>
 
 #include "blimp/common/create_blimp_message.h"
@@ skipping 76 matching lines @@
 void NavigationFeature::ProcessMessage(
     std::unique_ptr<BlimpMessage> message,
     const net::CompletionCallback& callback) {
   DCHECK(!callback.is_null());
   DCHECK_EQ(BlimpMessage::kNavigation, message->feature_case());
 
   int tab_id = message->target_tab_id();
   const NavigationMessage& navigation_message = message->navigation();
 
   NavigationFeatureDelegate* delegate = FindDelegate(tab_id);
-  DCHECK(delegate) << "NavigationFeatureDelegate not found for tab " << tab_id;
+  if (!delegate) {
+    VLOG(1) << "NavigationFeatureDelegate not found for " << tab_id
+            << ". Ignoring.";
+    callback.Run(net::OK);
+    return;
+  }
+
   switch (navigation_message.type()) {
     case NavigationMessage::NAVIGATION_STATE_CHANGED: {
       const NavigationStateChangeMessage& details =
           navigation_message.navigation_state_changed();
       if (details.has_url())
         delegate->OnUrlChanged(tab_id, GURL(details.url()));
 
       if (details.has_title())
         delegate->OnTitleChanged(tab_id, details.title());
 
@@ skipping 25 matching lines @@
     const int tab_id) {
   base::SmallMap<std::map<int, NavigationFeatureDelegate*>>::const_iterator it =
       delegates_.find(tab_id);
   if (it != delegates_.end())
     return it->second;
   return nullptr;
 }
 
 }  // namespace client
 }  // namespace blimp