diff --git chrome/browser/renderer_context_menu/render_view_context_menu.cc chrome/browser/renderer_context_menu/render_view_context_menu.cc
index de0d60b248414..7eae5ff63383a 100644
--- chrome/browser/renderer_context_menu/render_view_context_menu.cc
+++ chrome/browser/renderer_context_menu/render_view_context_menu.cc
@@ -359,6 +359,18 @@ base::OnceCallback<void(RenderViewContextMenu*)>* GetMenuShownCallback() {
   return callback.get();
 }
 
+RenderViewContextMenu::MenuCreatedCallback* GetMenuCreatedCallback() {
+  static base::NoDestructor<RenderViewContextMenu::MenuCreatedCallback>
+      callback;
+  return callback.get();
+}
+
+RenderViewContextMenu::MenuShowHandlerCallback* GetMenuShowHandlerCallback() {
+  static base::NoDestructor<RenderViewContextMenu::MenuShowHandlerCallback>
+      callback;
+  return callback.get();
+}
+
 enum class UmaEnumIdLookupType {
   GeneralEnumId,
   ContextSpecificEnumId,
@@ -620,6 +632,10 @@ int FindUMAEnumValueForCommand(int id, UmaEnumIdLookupType type) {
   if (ContextMenuMatcher::IsExtensionsCustomCommandId(id))
     return 1;
 
+  // Match the MENU_ID_USER_FIRST to MENU_ID_USER_LAST range from cef_types.h.
+  if (id >= 26500 && id <= 28500)
+    return 1;
+
   id = CollapseCommandsForUMA(id);
   const auto& map = GetIdcToUmaMap(type);
   auto it = map.find(id);
@@ -879,6 +895,14 @@ RenderViewContextMenu::RenderViewContextMenu(
   pdf_ocr_submenu_model_ = std::make_unique<ui::SimpleMenuModel>(this);
 #endif  // BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
 
+  auto* cb = GetMenuCreatedCallback();
+  if (!cb->is_null()) {
+    first_observer_ = cb->Run(this);
+    if (first_observer_) {
+      observers_.AddObserver(first_observer_.get());
+    }
+  }
+
   observers_.AddObserver(&autofill_context_menu_manager_);
 }
 
@@ -1354,6 +1378,12 @@ void RenderViewContextMenu::InitMenu() {
           autofill::SuggestionHidingReason::kContextMenuOpened);
     }
   }
+
+  if (first_observer_) {
+    // Do this last so that the observer can optionally modify previously
+    // created items.
+    first_observer_->InitMenu(params_);
+  }
 }
 
 Profile* RenderViewContextMenu::GetProfile() const {
@@ -3590,6 +3620,26 @@ void RenderViewContextMenu::RegisterExecutePluginActionCallbackForTesting(
   execute_plugin_action_callback_ = std::move(cb);
 }
 
+// static
+void RenderViewContextMenu::RegisterMenuCreatedCallback(
+    MenuCreatedCallback cb) {
+  *GetMenuCreatedCallback() = cb;
+}
+
+// static
+void RenderViewContextMenu::RegisterMenuShowHandlerCallback(
+    MenuShowHandlerCallback cb) {
+  *GetMenuShowHandlerCallback() = cb;
+}
+
+bool RenderViewContextMenu::UseShowHandler() {
+  auto* cb = GetMenuShowHandlerCallback();
+  if (!cb->is_null() && cb->Run(this)) {
+    return true;
+  }
+  return false;
+}
+
 custom_handlers::ProtocolHandlerRegistry::ProtocolHandlerList
 RenderViewContextMenu::GetHandlersForLinkUrl() {
   custom_handlers::ProtocolHandlerRegistry::ProtocolHandlerList handlers =
diff --git chrome/browser/renderer_context_menu/render_view_context_menu.h chrome/browser/renderer_context_menu/render_view_context_menu.h
index d9f97fbdced53..60a01f70592a3 100644
--- chrome/browser/renderer_context_menu/render_view_context_menu.h
+++ chrome/browser/renderer_context_menu/render_view_context_menu.h
@@ -157,7 +157,21 @@ class RenderViewContextMenu
   }
 #endif
 
+  // Registers a callback that will be called each time a context menu is
+  // created.
+  using MenuCreatedCallback = base::RepeatingCallback<
+      std::unique_ptr<RenderViewContextMenuObserver>(RenderViewContextMenu*)>;
+  static void RegisterMenuCreatedCallback(MenuCreatedCallback cb);
+
+  // Registers a callback that will be called each time before context menu is
+  // shown. The callback should return true if the show has handled.
+  using MenuShowHandlerCallback = base::RepeatingCallback<
+      bool(RenderViewContextMenu*)>;
+  static void RegisterMenuShowHandlerCallback(MenuShowHandlerCallback cb);
+
  protected:
+  bool UseShowHandler();
+
   Profile* GetProfile() const;
 
   // This may return nullptr (e.g. for WebUI dialogs). Virtual to allow tests to
@@ -479,6 +493,9 @@ class RenderViewContextMenu
   //   built.
   bool is_protocol_submenu_valid_ = false;
 
+  // An observer returned via MenuCreatedCallback that will be called first.
+  std::unique_ptr<RenderViewContextMenuObserver> first_observer_;
+
   // An observer that handles spelling suggestions, "Add to dictionary", and
   // "Use enhanced spell check" items.
   std::unique_ptr<SpellingMenuObserver> spelling_suggestions_menu_observer_;
diff --git chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.h chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.h
index cb51224f9892c..b5a3946999d8f 100644
--- chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.h
+++ chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.h
@@ -29,6 +29,7 @@ class RenderViewContextMenuMacCocoa : public RenderViewContextMenuMac {
 
   // RenderViewContextMenu:
   void Show() override;
+  bool IsRunning() override;
 
  private:
   // RenderViewContextMenuViewsMac:
diff --git chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm
index b130e9768c2d6..3e46b2fe18d0a 100644
--- chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm
+++ chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm
@@ -68,6 +68,10 @@ RenderViewContextMenuMacCocoa::~RenderViewContextMenuMacCocoa() {
 }
 
 void RenderViewContextMenuMacCocoa::Show() {
+  if (UseShowHandler()) {
+    return;
+  }
+
   views::Widget* widget = views::Widget::GetTopLevelWidgetForNativeView(
       source_web_contents_->GetNativeView());
 
@@ -93,6 +97,10 @@ void RenderViewContextMenuMacCocoa::Show() {
                       views::ElementTrackerViews::GetContextForWidget(widget));
 }
 
+bool RenderViewContextMenuMacCocoa::IsRunning() {
+  return menu_controller_ && [menu_controller_ isMenuOpen];
+}
+
 void RenderViewContextMenuMacCocoa::CancelToolkitMenu() {
   [menu_controller_ cancel];
 }
diff --git chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.h chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.h
index fb86992cee93f..fe674fe471cc4 100644
--- chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.h
+++ chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.h
@@ -27,6 +27,7 @@ class RenderViewContextMenuMacRemoteCocoa : public RenderViewContextMenuMac {
 
   // RenderViewContextMenu:
   void Show() override;
+  bool IsRunning() override;
 
  private:
   // RenderViewContextMenuViewsMac:
diff --git chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.mm chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.mm
index 9f6c5fd44f206..dc50bc909897f 100644
--- chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.mm
+++ chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_remote_cocoa.mm
@@ -42,6 +42,10 @@ void RenderViewContextMenuMacRemoteCocoa::Show() {
       target_view_id_);
 }
 
+bool RenderViewContextMenuMacRemoteCocoa::IsRunning() {
+  return runner_ && runner_->IsRunning();
+}
+
 void RenderViewContextMenuMacRemoteCocoa::CancelToolkitMenu() {
   runner_->Cancel();
 }
diff --git chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc
index c88a77a0b49e2..31b7224a36ae8 100644
--- chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc
+++ chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc
@@ -149,6 +149,9 @@ void RenderViewContextMenuViews::RunMenuAt(views::Widget* parent,
 bool RenderViewContextMenuViews::GetAcceleratorForCommandId(
     int command_id,
     ui::Accelerator* accel) const {
+  if (RenderViewContextMenu::GetAcceleratorForCommandId(command_id, accel))
+    return true;
+
   // There are no formally defined accelerators we can query so we assume
   // that Ctrl+C, Ctrl+V, Ctrl+X, Ctrl-A, etc do what they normally do.
   switch (command_id) {
@@ -385,6 +388,10 @@ void RenderViewContextMenuViews::AppendPlatformEditableItems() {
 }
 
 void RenderViewContextMenuViews::Show() {
+  if (UseShowHandler()) {
+    return;
+  }
+
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kKioskMode))
     return;
 
@@ -427,6 +434,11 @@ void RenderViewContextMenuViews::Show() {
   }
 }
 
+bool RenderViewContextMenuViews::IsRunning() {
+  return static_cast<ToolkitDelegateViews*>(toolkit_delegate())
+             ->IsMenuRunning();
+}
+
 views::Widget* RenderViewContextMenuViews::GetTopLevelWidget() {
   return views::Widget::GetTopLevelWidgetForNativeView(GetActiveNativeView());
 }
diff --git chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.h chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.h
index 55ba34c417e4a..e92f668868e74 100644
--- chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.h
+++ chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.h
@@ -45,6 +45,7 @@ class RenderViewContextMenuViews : public RenderViewContextMenu {
 
   // RenderViewContextMenuBase implementation.
   void Show() override;
+  bool IsRunning() override;
 
  protected:
   RenderViewContextMenuViews(content::RenderFrameHost& render_frame_host,
diff --git chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.cc chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.cc
index eb855deeb6040..3ff97b28fa4c6 100644
--- chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.cc
+++ chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.cc
@@ -91,6 +91,10 @@ void ChromeWebContentsViewDelegateViews::ShowMenu(
   context_menu_->Show();
 }
 
+bool ChromeWebContentsViewDelegateViews::IsMenuRunning() {
+  return context_menu_ && context_menu_->IsRunning();
+}
+
 void ChromeWebContentsViewDelegateViews::ShowContextMenu(
     content::RenderFrameHost& render_frame_host,
     const content::ContextMenuParams& params) {
diff --git chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.h chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.h
index 97c98c8738965..96c142806d7b2 100644
--- chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.h
+++ chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views.h
@@ -55,6 +55,7 @@ class ChromeWebContentsViewDelegateViews
       content::RenderFrameHost& render_frame_host,
       const content::ContextMenuParams& params) override;
   void ShowMenu(std::unique_ptr<RenderViewContextMenuBase> menu) override;
+  bool IsMenuRunning() override;
 
  private:
   // The context menu is reset every time we show it, but we keep a pointer to
diff --git chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.h chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.h
index 07e5b3613a2df..293282690bd5a 100644
--- chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.h
+++ chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.h
@@ -55,6 +55,7 @@ class ChromeWebContentsViewDelegateViewsMac
       content::RenderFrameHost& render_frame_host,
       const content::ContextMenuParams& params) override;
   void ShowMenu(std::unique_ptr<RenderViewContextMenuBase> menu) override;
+  bool IsMenuRunning() override;
 
  private:
   content::RenderWidgetHostView* GetActiveRenderWidgetHostView() const;
diff --git chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.mm chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.mm
index 0e2cf71973741..e8d9c38b49b6c 100644
--- chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.mm
+++ chrome/browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_mac.mm
@@ -131,6 +131,10 @@ void ChromeWebContentsViewDelegateViewsMac::ShowMenu(
   context_menu_->Show();
 }
 
+bool ChromeWebContentsViewDelegateViewsMac::IsMenuRunning() {
+  return context_menu_ && context_menu_->IsRunning();
+}
+
 content::RenderWidgetHostView*
 ChromeWebContentsViewDelegateViewsMac::GetActiveRenderWidgetHostView() const {
   return web_contents_->GetTopLevelRenderWidgetHostView();
diff --git components/renderer_context_menu/context_menu_delegate.h components/renderer_context_menu/context_menu_delegate.h
index 042428f77f4ad..e4efd98ca45d5 100644
--- components/renderer_context_menu/context_menu_delegate.h
+++ components/renderer_context_menu/context_menu_delegate.h
@@ -45,6 +45,8 @@ class ContextMenuDelegate {
   // Displays the context menu.
   virtual void ShowMenu(std::unique_ptr<RenderViewContextMenuBase> menu) = 0;
 
+  virtual bool IsMenuRunning() = 0;
+
  private:
   raw_ptr<content::WebContents> web_contents_ = nullptr;
 };
diff --git components/renderer_context_menu/render_view_context_menu_base.cc components/renderer_context_menu/render_view_context_menu_base.cc
index 8e45cecb17039..e40115e23ee82 100644
--- components/renderer_context_menu/render_view_context_menu_base.cc
+++ components/renderer_context_menu/render_view_context_menu_base.cc
@@ -374,6 +374,17 @@ bool RenderViewContextMenuBase::IsCommandIdChecked(int id) const {
   return false;
 }
 
+bool RenderViewContextMenuBase::GetAcceleratorForCommandId(
+    int id,
+    ui::Accelerator* accelerator) const {
+  for (auto& observer : observers_) {
+    if (observer.IsCommandIdSupported(id))
+      return observer.GetAccelerator(id, accelerator);
+  }
+
+  return false;
+}
+
 void RenderViewContextMenuBase::ExecuteCommand(int id, int event_flags) {
   command_executed_ = true;
   RecordUsedItem(id);
diff --git components/renderer_context_menu/render_view_context_menu_base.h components/renderer_context_menu/render_view_context_menu_base.h
index 57b288bc885e6..9909899e3b5fe 100644
--- components/renderer_context_menu/render_view_context_menu_base.h
+++ components/renderer_context_menu/render_view_context_menu_base.h
@@ -85,8 +85,13 @@ class RenderViewContextMenuBase : public ui::SimpleMenuModel::Delegate,
   // Programmatically closes the context menu.
   void Cancel();
 
+  virtual bool IsRunning() = 0;
+
   const ui::SimpleMenuModel& menu_model() const { return menu_model_; }
   const content::ContextMenuParams& params() const { return params_; }
+  content::WebContents* source_web_contents() const {
+    return source_web_contents_;
+  }
 
   // Returns true if the specified command id is known and valid for
   // this menu. If the command is known |enabled| is set to indicate
@@ -95,6 +100,9 @@ class RenderViewContextMenuBase : public ui::SimpleMenuModel::Delegate,
 
   // SimpleMenuModel::Delegate implementation.
   bool IsCommandIdChecked(int command_id) const override;
+  bool GetAcceleratorForCommandId(
+      int command_id,
+      ui::Accelerator* accelerator) const override;
   void ExecuteCommand(int command_id, int event_flags) override;
   void OnMenuWillShow(ui::SimpleMenuModel* source) override;
   void MenuClosed(ui::SimpleMenuModel* source) override;
diff --git components/renderer_context_menu/render_view_context_menu_observer.cc components/renderer_context_menu/render_view_context_menu_observer.cc
index 9fdda1636003d..538bd05a41296 100644
--- components/renderer_context_menu/render_view_context_menu_observer.cc
+++ components/renderer_context_menu/render_view_context_menu_observer.cc
@@ -15,3 +15,8 @@ bool RenderViewContextMenuObserver::IsCommandIdChecked(int command_id) {
 bool RenderViewContextMenuObserver::IsCommandIdEnabled(int command_id) {
   return false;
 }
+
+bool RenderViewContextMenuObserver::GetAccelerator(int command_id,
+                                                   ui::Accelerator* accel) {
+  return false;
+}
diff --git components/renderer_context_menu/render_view_context_menu_observer.h components/renderer_context_menu/render_view_context_menu_observer.h
index 0527c57abd51c..70bebcbb50461 100644
--- components/renderer_context_menu/render_view_context_menu_observer.h
+++ components/renderer_context_menu/render_view_context_menu_observer.h
@@ -11,6 +11,10 @@ namespace content {
 struct ContextMenuParams;
 }
 
+namespace ui {
+class Accelerator;
+}
+
 // The interface used for implementing context-menu items. The following
 // instruction describe how to implement a context-menu item with this
 // interface.
@@ -100,6 +104,8 @@ class RenderViewContextMenuObserver {
   virtual bool IsCommandIdChecked(int command_id);
   virtual bool IsCommandIdEnabled(int command_id);
 
+  virtual bool GetAccelerator(int command_id, ui::Accelerator* accel);
+
   // Called when a user selects the specified context-menu item. This is
   // only called when the observer returns true for IsCommandIdSupported()
   // for that |command_id|.
diff --git components/renderer_context_menu/views/toolkit_delegate_views.cc components/renderer_context_menu/views/toolkit_delegate_views.cc
index 823f044316527..85439bf7ad2eb 100644
--- components/renderer_context_menu/views/toolkit_delegate_views.cc
+++ components/renderer_context_menu/views/toolkit_delegate_views.cc
@@ -30,6 +30,10 @@ void ToolkitDelegateViews::RunMenuAt(views::Widget* parent,
                           anchor_position, type);
 }
 
+bool ToolkitDelegateViews::IsMenuRunning() const {
+  return menu_runner_ && menu_runner_->IsRunning();
+}
+
 void ToolkitDelegateViews::Init(ui::SimpleMenuModel* menu_model) {
   menu_adapter_ = std::make_unique<views::MenuModelAdapter>(menu_model);
   std::unique_ptr<views::MenuItemView> menu_view = menu_adapter_->CreateMenu();
diff --git components/renderer_context_menu/views/toolkit_delegate_views.h components/renderer_context_menu/views/toolkit_delegate_views.h
index eacdc12813204..9084effdaa121 100644
--- components/renderer_context_menu/views/toolkit_delegate_views.h
+++ components/renderer_context_menu/views/toolkit_delegate_views.h
@@ -39,6 +39,7 @@ class ToolkitDelegateViews : public RenderViewContextMenuBase::ToolkitDelegate {
                  const gfx::Point& point,
                  ui::MenuSourceType type);
   views::MenuItemView* menu_view() { return menu_view_; }
+  bool IsMenuRunning() const;
 
  protected:
   // ToolkitDelegate: