Refactor GlobalShortcutListener.

chrome/browser/extensions/extension_commands_global_registry.cc

 // Copyright (c) 2013 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 "chrome/browser/extensions/extension_commands_global_registry.h"
 
 #include "base/lazy_instance.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/api/commands/command_service.h"
 #include "chrome/browser/extensions/extension_keybinding_registry.h"
@@ skipping 53 matching lines @@
           extension->id(),
           extensions::CommandService::ACTIVE_ONLY,
           extensions::CommandService::GLOBAL,
           &commands))
     return;
 
   extensions::CommandMap::const_iterator iter = commands.begin();
   for (; iter != commands.end(); ++iter) {
     if (!command_name.empty() && (iter->second.command_name() != command_name))
       continue;
+    const ui::Accelerator& accelerator = iter->second.accelerator();
 
     VLOG(0) << "Adding global keybinding for " << extension->name().c_str()
             << " " << command_name.c_str()
-            << " key: " << iter->second.accelerator().GetShortcutText();
+            << " key: " << accelerator.GetShortcutText();
 
-    event_targets_[iter->second.accelerator()].push_back(
-        std::make_pair(extension->id(), iter->second.command_name()));
-    // Shortcuts except media keys have only one target in the list. See comment
-    // about |event_targets_|.
-    if (!extensions::CommandService::IsMediaKey(iter->second.accelerator()))
-      DCHECK(event_targets_[iter->second.accelerator()].size() == 1);
+    size_t target_count =
+        event_targets_.find(accelerator) != event_targets_.end() ?
+            event_targets_[accelerator].size() : 0;
+    if (extensions::CommandService::IsMediaKey(accelerator) &&
+        target_count > 0U) {
+      event_targets_[accelerator].push_back(
+          std::make_pair(extension->id(), iter->second.command_name()));
+      continue;  // Shortcut listener already listening for this media key.
+    }
 
-    GlobalShortcutListener::GetInstance()->RegisterAccelerator(
-      iter->second.accelerator(), this);
+    DCHECK_EQ(0U, target_count);
+    if (GlobalShortcutListener::GetInstance()->RegisterAccelerator(
+            accelerator, this)) {
+      event_targets_[accelerator].push_back(
+          std::make_pair(extension->id(), iter->second.command_name()));
+    }

[Finnur, 2013/12/17 16:35:45]

Good catch. But I think a better alternative is (pseudo):

if (!mediakey || target_count == 0) {
  DCHECK_EQ(0U, target_count);
  if (!GlobalShortcutListener::GetInstance()->RegisterAccelerator(
      accelerator, this))
    continue;
}

event_targets_[accelerator].push_back(
    std::make_pair(extension->id(), iter->second.command_name()));

[zhchbin, 2013/12/18 01:53:07]

Done. See the newest patch, actually the problem is simple, sorry for messing
up.

   }
 }
 
 void ExtensionCommandsGlobalRegistry::RemoveExtensionKeybindingImpl(
     const ui::Accelerator& accelerator,
     const std::string& command_name) {
   VLOG(0) << "Removing keybinding for " << command_name.c_str();
 
   GlobalShortcutListener::GetInstance()->UnregisterAccelerator(
       accelerator, this);
 }
 
 void ExtensionCommandsGlobalRegistry::OnKeyPressed(
     const ui::Accelerator& accelerator) {
   ExtensionKeybindingRegistry::NotifyEventTargets(accelerator);
 }
 
 }  // namespace extensions