[Mac] Move UI item validation to UserInterfaceItemCommandHandler.

chrome/browser/ui/cocoa/chrome_event_processing_window.mm

Index: chrome/browser/ui/cocoa/chrome_event_processing_window.mm
diff --git a/chrome/browser/ui/cocoa/chrome_event_processing_window.mm b/chrome/browser/ui/cocoa/chrome_event_processing_window.mm
index b7b437d923f67200e1a961bb126a05312fb709a3..838609e4fdc91232e61ac435e46c67a21910ac33 100644
--- a/chrome/browser/ui/cocoa/chrome_event_processing_window.mm
+++ b/chrome/browser/ui/cocoa/chrome_event_processing_window.mm
@@ -14,6 +14,8 @@
       commandDispatcherDelegate_;
 }
 
+@synthesize commandHandler;
+
 - (instancetype)initWithContentRect:(NSRect)contentRect
                           styleMask:(NSUInteger)windowStyle
                             backing:(NSBackingStoreType)bufferingType
@@ -45,6 +47,14 @@
   return [super performKeyEquivalent:event];
 }
 
+- (void)commandDispatch:(id)sender {
+  [[self commandHandler] commandDispatch:sender window:self];
+}
+
+- (void)commandDispatchUsingKeyModifiers:(id)sender {
+  [[self commandHandler] commandDispatchUsingKeyModifiers:sender window:self];
+}
+
 // NSWindow overrides.
 
 - (BOOL)performKeyEquivalent:(NSEvent*)event {
@@ -56,4 +66,21 @@
     [super sendEvent:event];
 }
 
+// NSWindow overrides (NSUserInterfaceValidations implementation).
+
+- (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item {
+  // Since this class implements these selectors, |super| will always say they
+  // are enabled. Only use [super] to validate other selectors. If there is no
+  // command handler, defer to AppController.
+  if ([item action] == @selector(commandDispatch:) ||
+      [item action] == @selector(commandDispatchUsingKeyModifiers:)) {
+    return
+        [self commandHandler]
+            ? [[self commandHandler] validateUserInterfaceItem:item window:self]
+            : [[NSApp delegate] validateUserInterfaceItem:item];
+  }
+
+  return [super validateUserInterfaceItem:item];
+}
+
 @end  // ChromeEventProcessingWindow