[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 646bcda011fd4cb5b7c108a534dc0127feee28f4..6f27d46893af42b32bbb5be44528ba68c8ea0f48 100644
--- a/chrome/browser/ui/cocoa/chrome_event_processing_window.mm
+++ b/chrome/browser/ui/cocoa/chrome_event_processing_window.mm
@@ -21,6 +21,7 @@
     commandDispatcherDelegate_.reset(
         [[ChromeCommandDispatcherDelegate alloc] init]);
     [commandDispatcher_ setDelegate:commandDispatcherDelegate_];
+    [self setCommandHandler:commandDispatcherDelegate_];
   }
   return self;
 }
@@ -32,6 +33,8 @@
 
 // CommandDispatchingWindow implementation.
 
+@synthesize commandHandler;
+
 - (BOOL)redispatchKeyEvent:(NSEvent*)event {
   return [commandDispatcher_ redispatchKeyEvent:event];
 }
@@ -40,6 +43,18 @@
   return [super performKeyEquivalent:event];
 }
 
+- (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item {
+  return [[self commandHandler] validateUserInterfaceItem:item window:self];
+}
+
+- (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 {