Content shell: Javascript dialogs, first pass, just Mac for now.

chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm

Index: chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm b/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
index be7b5e430aabd9d5689b14f6d5179d00cebd30c5..2570c7642a6d297daeb3ebd339a739ee1232e049 100644
--- a/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
+++ b/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
@@ -20,13 +20,13 @@
 // going away. Is responsible for cleaning itself up.
 @interface JavaScriptAppModalDialogHelper : NSObject<NSAlertDelegate> {
  @private
-  NSAlert* alert_;
+  scoped_nsobject<NSAlert> alert_;
   NSTextField* textField_;  // WEAK; owned by alert_
 }
 
 - (NSAlert*)alert;
 - (NSTextField*)textField;
-- (void)alertDidEnd:(NSAlert *)alert
+- (void)alertDidEnd:(NSAlert*)alert
          returnCode:(int)returnCode
         contextInfo:(void*)contextInfo;
 
@@ -35,7 +35,7 @@
 @implementation JavaScriptAppModalDialogHelper
 
 - (NSAlert*)alert {
-  alert_ = [[NSAlert alloc] init];
+  alert_.reset([[NSAlert alloc] init]);
   return alert_;
 }
 
@@ -48,11 +48,6 @@
   return textField_;
 }
 
-- (void)dealloc {
-  [alert_ release];
-  [super dealloc];
-}
-
 // |contextInfo| is the JSModalDialogCocoa that owns us.
 - (void)alertDidEnd:(NSAlert*)alert
          returnCode:(int)returnCode
@@ -90,6 +85,7 @@
     }
   }
 }
+
 @end
 
 ////////////////////////////////////////////////////////////////////////////////