browser: Abstract message box dialog functions into its own header file.

chrome/browser/ui/cocoa/simple_message_box_mac.mm

+// Copyright (c) 2011 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/simple_message_box.h"
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/sys_string_conversions.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util_mac.h"
+
+namespace browser {
+
+void ShowErrorBox(gfx::NativeWindow parent,
+                  const string16& title,
+                  const string16& message) {
+  // Ignore the title; it's the window title on other platforms and ignorable.
+  NSAlert* alert = [[[NSAlert alloc] init] autorelease];
+  [alert addButtonWithTitle:l10n_util::GetNSString(IDS_OK)];
+  [alert setMessageText:base::SysUTF16ToNSString(message)];
+  [alert setAlertStyle:NSWarningAlertStyle];
+  [alert runModal];
+}
+
+bool ShowYesNoBox(gfx::NativeWindow parent,
+                  const string16& title,
+                  const string16& message) {
+  // Ignore the title; it's the window title on other platforms and ignorable.
+  NSAlert* alert = [[[NSAlert alloc] init] autorelease];
+  [alert setMessageText:base::SysUTF16ToNSString(message)];
+  [alert setAlertStyle:NSWarningAlertStyle];
+
+  [alert addButtonWithTitle:
+      l10n_util::GetNSString(IDS_CONFIRM_MESSAGEBOX_YES_BUTTON_LABEL)];
+  [alert addButtonWithTitle:
+      l10n_util::GetNSString(IDS_CONFIRM_MESSAGEBOX_NO_BUTTON_LABEL)];
+
+  NSInteger result = [alert runModal];
+  return result == NSAlertFirstButtonReturn;
+}
+
+}  // namespace browser