chrome: Add ability to handle chrome menu/keyboard commands (fixes issue #3280)

This change adds a CefCommandHandler::OnChromeCommand callback for optionally
handling Chrome commands triggered via menus or keyboard shortcuts. Supported
command IDs are listed in a new cef_command_ids.h header file.

To test: Run `cefclient --enable-chrome-runtime --hide-controls`. Most commands
will blocked and removed from context menus.

patch/patches/chrome_runtime_views.patch

@@ -1,5 +1,5 @@
 diff --git chrome/browser/ui/browser_command_controller.cc chrome/browser/ui/browser_command_controller.cc
-index cff1df2490bb6..9d156bd9993fa 100644
+index cff1df2490bb6..864a03a2e29c9 100644
 --- chrome/browser/ui/browser_command_controller.cc
 +++ chrome/browser/ui/browser_command_controller.cc
 @@ -371,8 +371,10 @@ bool BrowserCommandController::ExecuteCommandWithDisposition(
@@ -14,7 +14,21 @@ index cff1df2490bb6..9d156bd9993fa 100644
  
    // No commands are enabled if there is not yet any selected tab.
    // TODO(pkasting): It seems like we should not need this, because either
-@@ -985,11 +987,13 @@ void BrowserCommandController::TabRestoreServiceLoaded(
+@@ -387,6 +389,13 @@ bool BrowserCommandController::ExecuteCommandWithDisposition(
+   DCHECK(command_updater_.IsCommandEnabled(id))
+       << "Invalid/disabled command " << id;
+ 
++#if BUILDFLAG(ENABLE_CEF)
++  if (browser_->cef_delegate() &&
++      browser_->cef_delegate()->HandleCommand(id, disposition)) {
++    return true;
++  }
++#endif
++
+   // The order of commands in this switch statement must match the function
+   // declaration order in browser.h!
+   switch (id) {
+@@ -985,11 +994,13 @@ void BrowserCommandController::TabRestoreServiceLoaded(
  // BrowserCommandController, private:
  
  bool BrowserCommandController::IsShowingMainUI() {