Silence some compiler / analyser comlaints

Summary:
Silence a deprecated warning.
Fix a missing super bug.
Stop using an instance variable before initialization.

Reviewers: junius, #material_components_ios_owners

Reviewed By: junius, #material_components_ios_owners

Projects: #material_components_ios

Differential Revision: http://codereview.cc/D136

Author: Ian Gordon

demos/Pesto/Pesto/PestoAppDelegate.m

@@ -10,7 +10,12 @@ @implementation PestoAppDelegate
 - (BOOL)application:(UIApplication *)application
     didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
 
+  // setStatusBarHidden:withAnimation: was deprecated in iOS 9.
+  // Silence the related warning.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
   [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:NO];
+#pragma clang diagnostic pop
 
   PestoFlexibleHeaderContainerViewController *flexHeadContainerVC =
       [[PestoFlexibleHeaderContainerViewController alloc] init];

demos/Pesto/Pesto/PestoDetailViewController.m

@@ -159,6 +159,7 @@ - (void)viewDidLoad {
 }
 
 - (void)viewWillAppear:(BOOL)animated {
+  [super viewWillAppear:animated];
   [self loadImage];
 }
 

demos/Pesto/Pesto/PestoFlexibleHeaderContainerViewController.m

@@ -29,10 +29,11 @@ - (instancetype)init {
                                                sectionInset,
                                                sectionInset,
                                                sectionInset)];
-  _collectionViewController =
+  PestoCollectionViewController *collectionVC =
       [[PestoCollectionViewController alloc] initWithCollectionViewLayout:layout];
-  self = [super initWithContentViewController:_collectionViewController];
+  self = [super initWithContentViewController:collectionVC];
   if (self) {
+    _collectionViewController = collectionVC;
     _collectionViewController.flexHeaderContainerVC = self;
     _collectionViewController.delegate = self;
     [self setNeedsStatusBarAppearanceUpdate];