Fix a bunch of clang warnings/errors.

chrome/browser/cocoa/tabpose_window.h

Index: chrome/browser/cocoa/tabpose_window.h
diff --git a/chrome/browser/cocoa/tabpose_window.h b/chrome/browser/cocoa/tabpose_window.h
index 39958a2f316d027a1503e08ee8b630cf414634a9..fef3bbb98fbf59a137af129f68f4ed27393b0803 100644
--- a/chrome/browser/cocoa/tabpose_window.h
+++ b/chrome/browser/cocoa/tabpose_window.h
@@ -59,10 +59,10 @@ class TabStripModelObserverBridge;
 
   // Stores all preview layers. The order in here matches the order in
   // the tabstrip model.
-  scoped_nsobject<NSArray> allThumbnailLayers_;
+  scoped_nsobject<NSMutableArray> allThumbnailLayers_;
 
-  scoped_nsobject<NSArray> allFaviconLayers_;
-  scoped_nsobject<NSArray> allTitleLayers_;
+  scoped_nsobject<NSMutableArray> allFaviconLayers_;
+  scoped_nsobject<NSMutableArray> allTitleLayers_;
 
   // Manages the state of all layers.
   scoped_ptr<tabpose::TileSet> tileSet_;