Transfer serviceworker state during cross site navigations too.

base/id_map.h

 // Copyright (c) 2011 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.
 
 #ifndef BASE_ID_MAP_H_
 #define BASE_ID_MAP_H_
 
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 35 matching lines @@
   }
 
   ~IDMap() {
     // Many IDMap's are static, and hence will be destroyed on the main thread.
     // However, all the accesses may take place on another thread, such as the
     // IO thread. Detaching again to clean this up.
     DetachFromThread();
     Releaser<OS, 0>::release_all(&data_);
   }
 
-  // Sets whether Add should CHECK if passed in NULL data. Default is false.
+  // Sets whether Add and Replace should DCHECK if passed in NULL data.
+  // Default is false.
   void set_check_on_null_data(bool value) { check_on_null_data_ = value; }
 
   // Adds a view with an automatically generated unique ID. See AddWithID.
   KeyType Add(T* data) {
     DCHECK(CalledOnValidThread());
-    CHECK(!check_on_null_data_ || data);
+    DCHECK(!check_on_null_data_ || data);
     KeyType this_id = next_id_;
     DCHECK(data_.find(this_id) == data_.end()) << "Inserting duplicate item";
     data_[this_id] = data;
     next_id_++;
     return this_id;
   }
 
   // Adds a new data member with the specified ID. The ID must not be in
   // the list. The caller either must generate all unique IDs itself and use
   // this function, or allow this object to generate IDs and call Add. These
   // two methods may not be mixed, or duplicate IDs may be generated
   void AddWithID(T* data, KeyType id) {
     DCHECK(CalledOnValidThread());
-    CHECK(!check_on_null_data_ || data);
+    DCHECK(!check_on_null_data_ || data);
     DCHECK(data_.find(id) == data_.end()) << "Inserting duplicate item";
     data_[id] = data;
   }
 
   void Remove(KeyType id) {
     DCHECK(CalledOnValidThread());
     typename HashTable::iterator i = data_.find(id);
     if (i == data_.end()) {
       NOTREACHED() << "Attempting to remove an item not in the list";
       return;
     }
 
     if (iteration_depth_ == 0) {
       Releaser<OS, 0>::release(i->second);
       data_.erase(i);
     } else {
       removed_ids_.insert(id);
     }
   }
 
+  // Replaces the value for |id| with |new_data| and returns a pointer to the
+  // existing value. If there is no entry for |id|, the map is not altered and
+  // nullptr is returned. The OwnershipSemantics of the map have no effect on
+  // how the existing value is treated, the IDMap does not delete the existing
+  // value being replaced.
+  T* Replace(KeyType id, T* new_data) {
+    DCHECK(CalledOnValidThread());
+    DCHECK(!check_on_null_data_ || new_data);
+    typename HashTable::iterator i = data_.find(id);
+    if (i == data_.end()) {
+      NOTREACHED() << "Attempting to replace an item not in the list";
+      return nullptr;
+    }
+
+    T* temp = i->second;
+    i->second = new_data;
+    return temp;
+  }
+
   void Clear() {
     DCHECK(CalledOnValidThread());
     if (iteration_depth_ == 0) {
       Releaser<OS, 0>::release_all(&data_);
     } else {
       for (typename HashTable::iterator i = data_.begin();
            i != data_.end(); ++i)
         removed_ids_.insert(i->first);
     }
   }
@@ skipping 143 matching lines @@
 
   HashTable data_;
 
   // See description above setter.
   bool check_on_null_data_;
 
   DISALLOW_COPY_AND_ASSIGN(IDMap);
 };
 
 #endif  // BASE_ID_MAP_H_