[ios] Remove unused and unneeded BVC methods.

This CL removes -resetAllWebviews, which no longer has any call sites.

This CL also removes -ensureViewCreated, which is just our implementation
of [UIViewController loadViewIfNeeded], which has been available since
iOS9. 

Bug: 
Change-Id: Ia2adab95a7a5726114a7e81ce784aaa4e40aa676
Reviewed-on: https://chromium-review.googlesource.com/570019
Commit-Queue: Mark Cogan <marq@chromium.org>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487434}

ios/chrome/app/main_controller.mm

@@ -1883,7 +1883,7 @@ enum class StackViewDismissalMode { NONE, NORMAL, INCOGNITO };
 - (id<ToolbarOwner>)tabSwitcherTransitionToolbarOwner {
   // Request the view to ensure that the view has been loaded and initialized,
   // since it may never have been loaded (or have been swapped out).
-  [self.currentBVC ensureViewCreated];
+  [self.currentBVC loadViewIfNeeded];
   return self.currentBVC;
 }
 

ios/chrome/browser/ui/browser_view_controller.h

@@ -107,10 +107,6 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint
 // Called when a UI element to create a new tab is triggered.
 - (void)newTab:(id)sender;
 
-// Makes sure that the view hierarchy has been built. Equivalent to calling
-// -view, but without the annoying compiler warning.
-- (void)ensureViewCreated;
-
 // Called when the browser state provided to this instance is being destroyed.
 // At this point the browser will no longer ever be active, and will likely be
 // deallocated soon.
@@ -128,11 +124,6 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint
                       atIndex:(NSUInteger)position
                    transition:(ui::PageTransition)transition;
 
-// This will dismiss the web views on all the tabs and reload the frontmost one
-// if there is one. This is used when a userdefault changes and the web views
-// need to be re-created to pick it up.
-- (void)resetAllWebViews;
-
 // Informs the BVC that a new foreground tab is about to be opened. This is
 // intended to be called before setWebUsageSuspended:NO in cases where a new tab
 // is about to appear in order to allow the BVC to avoid doing unnecessary work

ios/chrome/browser/ui/browser_view_controller.mm

@@ -1047,7 +1047,7 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint {
     // tab if the caller is about to create one) ends up on screen completely.
     Tab* currentTab = [_model currentTab];
     // Force loading the view in case it was not loaded yet.
-    [self ensureViewCreated];
+    [self loadViewIfNeeded];
     if (_expectingForegroundTab)
       [currentTab.webController setOverlayPreviewMode:YES];
     if (currentTab)
@@ -1730,10 +1730,6 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint {
   }
 }
 
-- (void)ensureViewCreated {
-  ignore_result([self view]);
-}
-
 - (void)browserStateDestroyed {
   [self setActive:NO];
   // Reset the toolbar opacity in case it was changed for contextual search.
@@ -1934,12 +1930,8 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint {
 
 - (void)displayTab:(Tab*)tab isNewSelection:(BOOL)newSelection {
   DCHECK(tab);
-  // Ensure that self.view is loaded to avoid errors that can otherwise occur
-  // when accessing |_contentArea| below.
-  if (!_contentArea)
-    [self ensureViewCreated];
+  [self loadViewIfNeeded];
 
-  DCHECK(_contentArea);
   if (!self.inNewTabAnimation) {
     // Hide findbar.  |updateToolbar| will restore the findbar later.
     [self hideFindBarWithAnimation:NO];
@@ -4335,11 +4327,6 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint {
                   appendTo:kCurrentTab];
 }
 
-- (void)resetAllWebViews {
-  [_dialogPresenter cancelAllDialogs];
-  [_model resetAllWebViews];
-}
-
 #pragma mark - Find Bar
 
 - (void)hideFindBarWithAnimation:(BOOL)animate {

ios/chrome/browser/ui/tab_switcher/tab_switcher_transition_context.mm

@@ -35,7 +35,7 @@
   transitionContextContent.initialTabID = bvc.tabModel.currentTab.tabId;
 
   if (![bvc isViewLoaded]) {
-    [bvc ensureViewCreated];
+    [bvc loadViewIfNeeded];
     [bvc.view setFrame:[[UIScreen mainScreen] bounds]];
   }