[CRD iOS] Add the host setup instruction page

remoting/ios/app/host_collection_view_controller.mm

Index: remoting/ios/app/host_collection_view_controller.mm
diff --git a/remoting/ios/app/host_collection_view_controller.mm b/remoting/ios/app/host_collection_view_controller.mm
index 72945970e7d85dd75db9bc7faf86a5aebd876b62..ed3a02ae523173739d21c52fd7584247e1b679b7 100644
--- a/remoting/ios/app/host_collection_view_controller.mm
+++ b/remoting/ios/app/host_collection_view_controller.mm
@@ -23,8 +23,7 @@ static CGFloat kHostCollectionHeaderViewHeight = 25.f;
 @implementation HostCollectionViewController
 
 @synthesize delegate = _delegate;
-@synthesize flexHeaderContainerViewController =
-    _flexHeaderContainerViewController;
+@synthesize scrollViewDelegate = _scrollViewDelegate;
 
 - (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout*)layout {
   self = [super initWithCollectionViewLayout:layout];
@@ -115,8 +114,7 @@ static CGFloat kHostCollectionHeaderViewHeight = 25.f;
 #pragma mark - UIScrollViewDelegate
 
 - (void)scrollViewDidScroll:(UIScrollView*)scrollView {
-  [self.flexHeaderContainerViewController.headerViewController
-      scrollViewDidScroll:scrollView];
+  [_scrollViewDelegate scrollViewDidScroll:scrollView];
 }
 
 #pragma mark - UICollectionViewDelegateFlowLayout
@@ -129,24 +127,4 @@ static CGFloat kHostCollectionHeaderViewHeight = 25.f;
                     kHostCollectionHeaderViewHeight);
 }
 
-#pragma mark - Private
-
-- (void)setFlexHeaderContainerViewController:
-    (MDCFlexibleHeaderContainerViewController*)
-        flexHeaderContainerViewController {
-  _flexHeaderContainerViewController = flexHeaderContainerViewController;
-  MDCFlexibleHeaderView* headerView =
-      _flexHeaderContainerViewController.headerViewController.headerView;
-  headerView.trackingScrollView = self.collectionView;
-  headerView.backgroundColor = [UIColor clearColor];
-
-  // Use a custom shadow under the flexible header.
-  MDCShadowLayer* shadowLayer = [MDCShadowLayer layer];

[Yuwei, 2017/06/26 23:31:13]

This logic has been moved to RemotingViewController to be shared with
HostSetupVC

-  [headerView setShadowLayer:shadowLayer
-      intensityDidChangeBlock:^(CALayer* layer, CGFloat intensity) {
-        CGFloat elevation = MDCShadowElevationAppBar * intensity;
-        [(MDCShadowLayer*)layer setElevation:elevation];
-      }];
-}
-
 @end