extensions: Make sure a valid key is used to track the event-listener counts.

extensions/renderer/event_bindings.cc

 // Copyright 2014 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 "extensions/renderer/event_bindings.h"
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
+#include "components/crx_file/id_util.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
 #include "content/public/renderer/v8_value_converter.h"
 #include "extensions/common/event_filter.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/manifest_handlers/background_info.h"
 #include "extensions/common/value_counter.h"
 #include "extensions/renderer/dispatcher.h"
 #include "extensions/renderer/extension_helper.h"
@@ skipping 20 matching lines @@
 // between 0 and 1.
 typedef std::map<std::string, linked_ptr<ValueCounter> >
     FilteredEventListenerCounts;
 
 // A map of extension IDs to filtered listener counts for that extension.
 base::LazyInstance<std::map<std::string, FilteredEventListenerCounts> >
     g_filtered_listener_counts = LAZY_INSTANCE_INITIALIZER;
 
 base::LazyInstance<EventFilter> g_event_filter = LAZY_INSTANCE_INITIALIZER;
 
+std::string GetKeyForScriptContext(ScriptContext* script_context) {
+  const std::string& extension_id = script_context->GetExtensionID();
+  CHECK(crx_file::id_util::IdIsValid(extension_id) ||
+        script_context->GetURL().is_valid());
+  return crx_file::id_util::IdIsValid(extension_id)
+             ? extension_id
+             : script_context->GetURL().spec();
+}
+
+// Increments the number of event-listeners for the given |event_name| and
+// ScriptContext. Returns the count after the increment.
+int IncrementEventListenerCount(ScriptContext* script_context,
+                                const std::string& event_name) {
+  return ++g_listener_counts
+               .Get()[GetKeyForScriptContext(script_context)][event_name];
+}
+
+// Decrements the number of event-listeners for the given |event_name| and
+// ScriptContext. Returns the count after the increment.
+int DecrementEventListenerCount(ScriptContext* script_context,
+                                const std::string& event_name) {
+  return --g_listener_counts
+               .Get()[GetKeyForScriptContext(script_context)][event_name];
+}
+
 bool IsLazyBackgroundPage(content::RenderView* render_view,
                           const Extension* extension) {
   if (!render_view)
     return false;
   ExtensionHelper* helper = ExtensionHelper::Get(render_view);
   return (extension && BackgroundInfo::HasLazyBackgroundPage(extension) &&
           helper->view_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
 }
 
 EventFilteringInfo ParseFromObject(v8::Handle<v8::Object> object,
@@ skipping 74 matching lines @@
 void EventBindings::AttachEvent(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(1, args.Length());
   CHECK(args[0]->IsString());
 
   std::string event_name = *v8::String::Utf8Value(args[0]);
 
   if (!dispatcher_->CheckContextAccessToExtensionAPI(event_name, context()))
     return;
 
-  std::string extension_id = context()->GetExtensionID();
-  EventListenerCounts& listener_counts = g_listener_counts.Get()[extension_id];
-  if (++listener_counts[event_name] == 1) {
+  const std::string& extension_id = context()->GetExtensionID();
+  if (IncrementEventListenerCount(context(), event_name) == 1) {
     content::RenderThread::Get()->Send(new ExtensionHostMsg_AddListener(
         extension_id, context()->GetURL(), event_name));
   }
 
   // This is called the first time the page has added a listener. Since
   // the background page is the only lazy page, we know this is the first
   // time this listener has been registered.
   if (IsLazyBackgroundPage(context()->GetRenderView(),
                            context()->extension())) {
     content::RenderThread::Get()->Send(
         new ExtensionHostMsg_AddLazyListener(extension_id, event_name));
   }
 }
 
 void EventBindings::DetachEvent(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(2, args.Length());
   CHECK(args[0]->IsString());
   CHECK(args[1]->IsBoolean());
 
   std::string event_name = *v8::String::Utf8Value(args[0]);
   bool is_manual = args[1]->BooleanValue();
 
-  std::string extension_id = context()->GetExtensionID();
-  EventListenerCounts& listener_counts = g_listener_counts.Get()[extension_id];
-
-  if (--listener_counts[event_name] == 0) {
+  const std::string& extension_id = context()->GetExtensionID();
+  if (DecrementEventListenerCount(context(), event_name) == 0) {
     content::RenderThread::Get()->Send(new ExtensionHostMsg_RemoveListener(
         extension_id, context()->GetURL(), event_name));
   }
 
   // DetachEvent is called when the last listener for the context is
   // removed. If the context is the background page, and it removes the
   // last listener manually, then we assume that it is no longer interested
   // in being awakened for this event.
   if (is_manual && IsLazyBackgroundPage(context()->GetRenderView(),
                                         context()->extension())) {
@@ skipping 105 matching lines @@
 }
 
 scoped_ptr<EventMatcher> EventBindings::ParseEventMatcher(
     base::DictionaryValue* filter_dict) {
   return scoped_ptr<EventMatcher>(new EventMatcher(
       scoped_ptr<base::DictionaryValue>(filter_dict->DeepCopy()),
       context()->GetRenderView()->GetRoutingID()));
 }
 
 }  // namespace extensions