Made CrashingModules.plist non-updatable.

ios/chrome/app/safe_mode_crashing_modules_config.mm

 // Copyright 2013 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/chrome/app/safe_mode_crashing_modules_config.h"
 
 #include "base/logging.h"
+#include "base/mac/foundation_util.h"
+#import "base/mac/scoped_nsobject.h"
 
 namespace {
 
 NSString* const kStartupCrashModulesKey = @"StartupCrashModules";
 NSString* const kModuleFriendlyNameKey = @"ModuleFriendlyName";
 
 }  // namespace
 
+@interface SafeModeCrashingModulesConfig () {
+  base::scoped_nsobject<NSDictionary> _configuration;
+}
+@end
+
 @implementation SafeModeCrashingModulesConfig
 
 + (SafeModeCrashingModulesConfig*)sharedInstance {
   static SafeModeCrashingModulesConfig* instance =
       [[SafeModeCrashingModulesConfig alloc] init];
   return instance;
 }
 
 - (instancetype)init {
-  self = [super initWithAppId:nil version:nil plist:@"CrashingModules.plist"];
+  self = [super init];
   if (self) {
-    self.stopsUpdateChecksOnAppTermination = YES;
+    NSString* configPath =
+        [[NSBundle mainBundle] pathForResource:@"CrashingModules"
+                                        ofType:@"plist"];
+    _configuration.reset(
+        [[NSDictionary alloc] initWithContentsOfFile:configPath]);
   }
   return self;
 }
 
 - (NSString*)startupCrashModuleFriendlyName:(NSString*)modulePath {
-  NSDictionary* configData = [self dictionaryFromConfig];
-  NSDictionary* modules = [configData objectForKey:kStartupCrashModulesKey];
-  if (modules) {
-    DCHECK([modules isKindOfClass:[NSDictionary class]]);
-    NSDictionary* module = modules[modulePath];
-    if (module) {
-      DCHECK([module isKindOfClass:[NSDictionary class]]);
-      return module[kModuleFriendlyNameKey];
-    }
-  }
-  return nil;
+  NSDictionary* modules = base::mac::ObjCCastStrict<NSDictionary>(

[rohitrao (ping after 24h), 2016/07/15 17:23:19]

Does this method also get called during startup?  What happens if the cast
fails?  (What does modules[modulePath] do if modules is nil?  Should we be more
defensive here?)

[pkl (ping after 24h if needed), 2016/07/15 20:33:18]

This method is currently called from Safe Mode View Controller.

If modules in modules[modulePath] is nil, nil is returned.

ObjCCastStrict DCHECKs and returns nil if object is not a compatible type. Nil
will be returned from this method. The behavior of using ObjCCastStrict and
ObjCCast is equivalent to the replaced version, just less verbose.

+      [_configuration objectForKey:kStartupCrashModulesKey]);
+  NSDictionary* module =
+      base::mac::ObjCCastStrict<NSDictionary>(modules[modulePath]);
+  return base::mac::ObjCCast<NSString>(module[kModuleFriendlyNameKey]);
 }
 
 @end