Reload offline version on load failure

ios/web/web_state/ui/crw_web_controller.mm

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 1183 matching lines @@
 
   // WKWebView autoreleases its WKProcessPool on removal from superview.
   // Deferring WKProcessPool deallocation may lead to issues with cookie
   // clearing and and Browsing Data Partitioning implementation.
   @autoreleasepool {
     [self setNativeControllerWebUsageEnabled:_webUsageEnabled];
     if (enabled) {
       // Don't create the web view; let it be lazy created as needed.
     } else {
       [self clearTransientContentView];
+      if ([self.nativeController respondsToSelector:@selector(willBeDismissed)])
+        [self.nativeController willBeDismissed];
       [self removeWebViewAllowingCachedReconstruction:YES];
       _touchTrackingRecognizer.get().touchTrackingDelegate = nil;
       _touchTrackingRecognizer.reset();
       [self resetContainerView];
     }
   }
 }
 
 - (void)requirePageReconstruction {
   [self removeWebViewAllowingCachedReconstruction:NO];
@@ skipping 57 matching lines @@
 }
 
 // Caller must reset the delegate before calling.
 - (void)close {
   _webStateImpl->CancelDialogs();
 
   _SSLStatusUpdater.reset();
 
   self.nativeProvider = nil;
   self.swipeRecognizerProvider = nil;
+  if ([self.nativeController respondsToSelector:@selector(willBeDismissed)])
+    [self.nativeController willBeDismissed];
   if ([self.nativeController respondsToSelector:@selector(close)])
     [self.nativeController close];
 
   base::scoped_nsobject<NSSet> observers([_observers copy]);
   for (id it in observers.get()) {
     if ([it respondsToSelector:@selector(webControllerWillClose:)])
       [it webControllerWillClose:self];
   }
 
   if (!_isHalted) {
@@ skipping 720 matching lines @@
 
   // Initiating a navigation from the UI, record the current page state before
   // the new page loads. Don't record for back/forward, as the current entry
   // has already been moved to the next entry in the history. Do, however,
   // record it for general reload.
   // TODO(jimblackler): consider a single unified call to record state whenever
   // the page is about to be changed. This cannot currently be done after
   // addPendingEntry is called.
 
   [_delegate webWillInitiateLoadWithParams:params];
+  if ([self.nativeController respondsToSelector:@selector(willBeDismissed)]) {
+    [self.nativeController willBeDismissed];
+  }
 
   GURL navUrl = params.url;
   ui::PageTransition transition = params.transition_type;
 
   BOOL initialNavigation = NO;
   BOOL forwardBack =
       PageTransitionCoreTypeIs(transition, ui::PAGE_TRANSITION_RELOAD) &&
       (transition & ui::PAGE_TRANSITION_FORWARD_BACK);
   if (forwardBack) {
     // Setting these for back/forward is not supported.
@@ skipping 38 matching lines @@
 
 - (void)loadCurrentURL {
   // If the content view doesn't exist, the tab has either been evicted, or
   // never displayed. Bail, and let the URL be loaded when the tab is shown.
   if (!_containerView)
     return;
 
   // Reset current WebUI if one exists.
   [self clearWebUI];
 
+  if ([self.nativeController respondsToSelector:@selector(willBeDismissed)])
+    [self.nativeController willBeDismissed];

[Eugene But (OOO till 7-30), 2016/12/19 18:47:05]

It looks like |willBeDismissed| should be called only when
|clearTransientContentView| is called. To make this more maintainable, could you
please rename |clearTransientContentView| and move |willBeDismissed| call to
that renamed method.

[Olivier, 2016/12/20 12:29:47]

Done.

+
   // Abort any outstanding page load. This ensures the delegate gets informed
   // about the outgoing page, and further messages from the page are suppressed.
   if (_loadPhase != web::PAGE_LOADED)
     [self abortLoad];
 
   DCHECK(!_isHalted);
   // Remove the transient content view.
   [self clearTransientContentView];
 
   web::NavigationItem* item = [self currentNavItem];
@@ skipping 183 matching lines @@
 }
 
 - (void)goToItemAtIndex:(int)index {
   CRWSessionController* sessionController = self.sessionController;
   NSArray* entries = sessionController.entries;
   DCHECK_LT(static_cast<NSUInteger>(index), entries.count);
   DCHECK_GE(index, 0);
 
   if (!_webStateImpl->IsShowingWebInterstitial())
     [self recordStateInHistory];
+  if ([self.nativeController respondsToSelector:@selector(willBeDismissed)])

[Eugene But (OOO till 7-30), 2016/12/19 18:47:05]

|goToItemAtIndex:| calls |loadCurrentURL| or |loadWithParams|, and those 2
methods call willBeDismissed. So you probably don't need it here. 

[Olivier, 2016/12/20 12:29:47]

Done.

+    [self.nativeController willBeDismissed];
+
   CRWSessionEntry* fromEntry = self.sessionController.currentEntry;
 
   NSUserDefaults* userDefaults = [NSUserDefaults standardUserDefaults];
   if (![userDefaults boolForKey:@"PendingIndexNavigationDisabled"]) {
     BOOL sameDocumentNavigation =
         [sessionController isSameDocumentNavigationBetweenEntry:fromEntry
                                                        andEntry:entries[index]];
     if (sameDocumentNavigation) {
       [self.sessionController goToEntryAtIndex:index];
 
@@ skipping 2564 matching lines @@
                       if (loadError)
                         [self handleLoadError:loadError inMainFrame:YES];
                       else
                         self.webStateImpl->SetContentsMimeType("text/html");
                     }];
 }
 
 - (void)loadHTML:(NSString*)HTML forURL:(const GURL&)URL {
   // Remove the transient content view.
   [self clearTransientContentView];
+  if ([self.nativeController respondsToSelector:@selector(willBeDismissed)])
+    [self.nativeController willBeDismissed];
 
   _loadPhase = web::LOAD_REQUESTED;
 
   // Web View should not be created for App Specific URLs.
   if (!web::GetWebClient()->IsAppSpecificURL(URL)) {
     [self ensureWebViewCreated];
     DCHECK(_webView) << "_webView null while trying to load HTML";
   }
   [_webView loadHTMLString:HTML baseURL:net::NSURLWithGURL(URL)];
 }
@@ skipping 907 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end