Fix crash restoration to restore all windows correctly.

Also make sure that the restore prompt doesn't show if the user already
restored.


Bug: 1136307
Change-Id: I733202c348923224c20d5e8728cbab9cd21466d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2459804
Commit-Queue: Mark Cogan <marq@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815155}

ios/chrome/browser/crash_report/crash_restore_helper.h

@@ -15,6 +15,9 @@ class ChromeBrowserState;
 
 - (instancetype)initWithBrowser:(Browser*)browser;
 
+// Returns YES if a backup file for sessionID can be found on disk.
++ (BOOL)isBackedUpSessionID:(NSString*)sessionID;
+
 // Saves the session information stored on disk for sessions with |sessionIDs|
 // in temporary files and will then delete those from their default location.
 // This will ensure that the user will then start from scratch, while allowing

ios/chrome/browser/crash_report/crash_restore_helper.mm

@@ -232,12 +232,12 @@ int SessionCrashedInfoBarDelegate::GetIconId() const {
 @implementation CrashRestoreHelper {
   Browser* _browser;
   std::unique_ptr<InfoBarManagerObserverBridge> _infoBarBridge;
-
-  // Indicate that the session has been restored to tabs or to recently closed
-  // and should not be rerestored.
-  BOOL _sessionRestored;
 }
 
+// Indicate that the session has been restored to tabs or to recently closed
+// and should not be rerestored.
+static BOOL _sessionRestored = NO;
+
 - (instancetype)initWithBrowser:(Browser*)browser {
   if (self = [super init]) {
     _browser = browser;
@@ -408,6 +408,10 @@ int SessionCrashedInfoBarDelegate::GetIconId() const {
                           error:nil];
 }
 
++ (BOOL)isBackedUpSessionID:(NSString*)sessionID {
+  return [[[self class] backedupSessionIDs] containsObject:sessionID];
+}
+
 + (BOOL)moveAsideSessionInformationForBrowserState:
     (ChromeBrowserState*)browserState {
   DCHECK(!IsMultiwindowSupported());
@@ -488,10 +492,15 @@ int SessionCrashedInfoBarDelegate::GetIconId() const {
     NSString* originalSessionPath =
         [SessionServiceIOS sessionPathForSessionID:sessionID
                                          directory:stashPath];
-    [fileManager
-        moveItemAtPath:[[strongSelf class] backupPathForSessionID:sessionID]
+    NSString* backupPath =
+        [[strongSelf class] backupPathForSessionID:sessionID];
+    [fileManager moveItemAtPath:backupPath
                          toPath:originalSessionPath
                           error:&error];
+    // Remove Parent directory for the backup path, so it doesn't show restore
+    // prompt again.
+    [fileManager removeItemAtPath:[backupPath stringByDeletingLastPathComponent]
+                            error:&error];
   }
 
   return success;

ios/chrome/browser/ui/main/scene_controller.mm

@@ -614,11 +614,16 @@ const char kMultiWindowOpenInNewWindowHistogram[] =
     }
   }
 
-  // Only create the restoration helper if the browser state was backed up
-  // successfully.
+  // Only create the restoration helper if the session with the current session
+  // id was backed up successfully.
   if (self.sceneState.appState.sessionRestorationRequired) {
+    if (!IsMultiwindowSupported() ||
+        [CrashRestoreHelper
+            isBackedUpSessionID:self.sceneState.sceneSessionID]) {
       self.sceneState.appState.startupInformation.restoreHelper =
-        [[CrashRestoreHelper alloc] initWithBrowser:self.mainInterface.browser];
+          [[CrashRestoreHelper alloc]
+              initWithBrowser:self.mainInterface.browser];
+    }
   }
 
   // Before bringing up the UI, make sure the launch mode is correct, and