Revert of Remove support for GlobalNetworkClientFactory from RequestTracker.

ios/net/request_tracker.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.
 
 #include "ios/net/request_tracker.h"
 
 #include "base/logging.h"
 #import "ios/net/clients/crn_forwarding_network_client.h"
 #import "ios/net/clients/crn_forwarding_network_client_factory.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace net {
 
 namespace {
 
 // Reference to the single instance of the RequestTrackerFactory.
 RequestTracker::RequestTrackerFactory* g_request_tracker_factory = nullptr;
 
+// Array of network client factories that should be added to any new request
+// tracker.
+class GlobalNetworkClientFactories {
+ public:
+  static GlobalNetworkClientFactories* GetInstance() {
+    if (!g_global_network_client_factories)
+      g_global_network_client_factories = new GlobalNetworkClientFactories;
+    return g_global_network_client_factories;
+  }
+
+  // Gets the factories.
+  NSArray* GetFactories() {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    return factories_.get();
+  }
+
+  // Adds a factory.
+  void AddFactory(CRNForwardingNetworkClientFactory* factory) {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK_EQ(NSNotFound,
+              static_cast<NSInteger>([factories_ indexOfObject:factory]));
+    DCHECK(!IsSelectorOverriden(factory, @selector(clientHandlingRequest:)));
+    DCHECK(!IsSelectorOverriden(factory,
+                                @selector(clientHandlingResponse:request:)));
+    DCHECK(!IsSelectorOverriden(
+               factory, @selector(clientHandlingRedirect:url:response:)));
+    [factories_ addObject:factory];
+  }
+
+  // Returns true if |factory| re-implements |selector|.
+  // Only used for debugging.
+  bool IsSelectorOverriden(CRNForwardingNetworkClientFactory* factory,
+                           SEL selector) {
+    return
+        [factory methodForSelector:selector] !=
+        [CRNForwardingNetworkClientFactory instanceMethodForSelector:selector];
+  }
+
+ private:
+  GlobalNetworkClientFactories() : factories_([[NSMutableArray alloc] init]) {}
+
+  base::scoped_nsobject<NSMutableArray> factories_;
+  base::ThreadChecker thread_checker_;
+
+  static GlobalNetworkClientFactories* g_global_network_client_factories;
+};
+
+GlobalNetworkClientFactories*
+    GlobalNetworkClientFactories::g_global_network_client_factories = nullptr;
+
 }  // namespace
 
 RequestTracker::RequestTrackerFactory::~RequestTrackerFactory() {
 }
 
 // static
 void RequestTracker::SetRequestTrackerFactory(RequestTrackerFactory* factory) {
   g_request_tracker_factory = factory;
 }
 
@@ skipping 19 matching lines @@
                                                            NSUInteger idx,
                                                            BOOL* stop) {
       return [obj clientClass] == [factory clientClass];
   }] == NSNotFound);
   [client_factories_ addObject:factory];
   if ([factory requiresOrdering]) {
     [client_factories_ sortUsingSelector:@selector(orderRelativeTo:)];
   }
 }
 
+// static
+void RequestTracker::AddGlobalNetworkClientFactory(
+    CRNForwardingNetworkClientFactory* factory) {
+  GlobalNetworkClientFactories::GetInstance()->AddFactory(factory);
+}
+
 RequestTracker::RequestTracker()
     : client_factories_([[NSMutableArray alloc] init]),
       initialized_(false),
       cache_mode_(CACHE_NORMAL),
       weak_ptr_factory_(this) {
   // RequestTracker can be created from the main thread and used from another
   // thread.
   thread_checker_.DetachFromThread();
 }
 
 RequestTracker::~RequestTracker() {
 }
 
 base::WeakPtr<RequestTracker> RequestTracker::GetWeakPtr() {
   return weak_ptr_factory_.GetWeakPtr();
 }
 
 void RequestTracker::InvalidateWeakPtrs() {
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
 void RequestTracker::Init() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!initialized_);
   initialized_ = true;
+  for (CRNForwardingNetworkClientFactory* factory in
+           GlobalNetworkClientFactories::GetInstance()->GetFactories()) {
+    AddNetworkClientFactory(factory);
+  }
+}
+
+// static
+NSArray* RequestTracker::GlobalClientsHandlingAnyRequest() {
+  NSMutableArray* applicable_clients = [NSMutableArray array];
+  for (CRNForwardingNetworkClientFactory* factory in
+           GlobalNetworkClientFactories::GetInstance()->GetFactories()) {
+    CRNForwardingNetworkClient* client = [factory clientHandlingAnyRequest];
+    if (client)
+      [applicable_clients addObject:client];
+  }
+  return applicable_clients;
 }
 
 NSArray* RequestTracker::ClientsHandlingAnyRequest() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(initialized_);
   NSMutableArray* applicable_clients = [NSMutableArray array];
   for (CRNForwardingNetworkClientFactory* factory in client_factories_.get()) {
     CRNForwardingNetworkClient* client = [factory clientHandlingAnyRequest];
     if (client)
       [applicable_clients addObject:client];
@@ skipping 51 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   return cache_mode_;
 }
 
 void RequestTracker::SetCacheMode(RequestTracker::CacheMode mode) {
   DCHECK(thread_checker_.CalledOnValidThread());
   cache_mode_ = mode;
 }
 
 }  // namespace net