Fix a bunch of clang warnings/errors.

chrome/browser/cocoa/sidebar_controller.mm

 // Copyright (c) 2010 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.
 
 #import "chrome/browser/cocoa/sidebar_controller.h"
 
 #include <algorithm>
 
 #include <Cocoa/Cocoa.h>
 
@@ skipping 35 matching lines @@
     sidebarContents_ = NULL;
   }
   return self;
 }
 
 - (void)dealloc {
   [splitView_ setDelegate:nil];
   [super dealloc];
 }
 
-- (NSView*)view {
+- (NSSplitView*)view {
   return splitView_.get();
 }
 
 - (NSSplitView*)splitView {
   return splitView_.get();
 }
 
 - (void)updateSidebarForTabContents:(TabContents*)contents {
   // Get the active sidebar content.
   if (SidebarManager::GetInstance() == NULL)  // Happens in tests.
@@ skipping 94 matching lines @@
 - (BOOL)splitView:(NSSplitView *)splitView
     shouldAdjustSizeOfSubview:(NSView *)subview {
   // Return NO for the sidebar view to indicate that it should not be resized
   // automatically.  The sidebar keeps the width set by the user.
   if ([[splitView_ subviews] indexOfObject:subview] == 1)
     return NO;
   return YES;
 }
 
 @end