Fix a number of issues with iOS build.

Set pointer to root view in window (for SampleApp)
Set up the correct function pointer for GL multisampling
Remove use of SkBitmap::setConfig()
Remove incomplete iOS implementation of SkFILE (use SkOSFile for now)

R=caryclark@google.com, reed@google.com, bsalomon@google.com, tfarina@chromium.org

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/322403007
diff --git a/experimental/iOSSampleApp/iPad/AppDelegate_iPad.mm b/experimental/iOSSampleApp/iPad/AppDelegate_iPad.mm
index d0aeaf2..c33fdde 100644
--- a/experimental/iOSSampleApp/iPad/AppDelegate_iPad.mm
+++ b/experimental/iOSSampleApp/iPad/AppDelegate_iPad.mm
@@ -7,6 +7,9 @@
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     [window addSubview:[splitViewController view]];
     [window makeKeyAndVisible];
+
+    self.window.rootViewController = splitViewController;
+
     return YES;
 }