[iOS/ARC] Fix a violation of ODR in base::BindBlock under ARC.

ios/web/net/request_tracker_impl.mm

Index: ios/web/net/request_tracker_impl.mm
diff --git a/ios/web/net/request_tracker_impl.mm b/ios/web/net/request_tracker_impl.mm
index 508e5ae275d5367a381ab83ace84319302572673..9bb48e30d18d5ae21638a87552587f739a35d076 100644
--- a/ios/web/net/request_tracker_impl.mm
+++ b/ios/web/net/request_tracker_impl.mm
@@ -484,8 +484,7 @@ void RequestTrackerImpl::StartRequest(net::URLRequest* request) {
   if (!is_for_static_file_requests_ && addedRequest) {
     NSString* networkActivityKey = GetNetworkActivityKey();
     web::WebThread::PostTask(
-        web::WebThread::UI, FROM_HERE,
-        base::BindBlock(^{
+        web::WebThread::UI, FROM_HERE, base::BindBlockArc(^{
           [[CRWNetworkActivityIndicatorManager sharedInstance]
               startNetworkTaskForGroup:networkActivityKey];
         }));
@@ -565,8 +564,7 @@ void RequestTrackerImpl::StopRequest(net::URLRequest* request) {
   if (!is_for_static_file_requests_ && removedRequests > 0) {
     NSString* networkActivityKey = GetNetworkActivityKey();
     web::WebThread::PostTask(
-        web::WebThread::UI, FROM_HERE,
-        base::BindBlock(^{
+        web::WebThread::UI, FROM_HERE, base::BindBlockArc(^{
           [[CRWNetworkActivityIndicatorManager sharedInstance]
               stopNetworkTaskForGroup:networkActivityKey];
         }));
@@ -585,8 +583,7 @@ void RequestTrackerImpl::StopRedirectedRequest(net::URLRequest* request) {
   if (!is_for_static_file_requests_ && removedRequests > 0) {
     NSString* networkActivityKey = GetNetworkActivityKey();
     web::WebThread::PostTask(
-        web::WebThread::UI, FROM_HERE,
-        base::BindBlock(^{
+        web::WebThread::UI, FROM_HERE, base::BindBlockArc(^{
           [[CRWNetworkActivityIndicatorManager sharedInstance]
               stopNetworkTaskForGroup:networkActivityKey];
         }));
@@ -748,7 +745,7 @@ void RequestTrackerImplTraits::Destruct(const RequestTrackerImpl* t) {
     // destroyed, the object inconstant_t points to won't be deleted while
     // the block is executing (and Destruct() itself will do the deleting).
     web::WebThread::PostTask(web::WebThread::IO, FROM_HERE,
-                             base::BindBlock(^{
+                             base::BindBlockArc(^{
                                inconstant_t->Destruct();
                              }));
   }
@@ -765,9 +762,9 @@ void RequestTrackerImpl::Destruct() {
   }
   InvalidateWeakPtrs();
   // Delete on the UI thread.
-  web::WebThread::PostTask(web::WebThread::UI, FROM_HERE, base::BindBlock(^{
-                                                            delete this;
-                                                          }));
+  web::WebThread::PostTask(web::WebThread::UI, FROM_HERE, base::BindBlockArc(^{
+                             delete this;
+                           }));
 }
 
 #pragma mark Other private methods
@@ -1300,8 +1297,7 @@ void RequestTrackerImpl::CancelRequests() {
   if (!is_for_static_file_requests_ && removedRequests > 0) {
     NSString* networkActivityKey = GetNetworkActivityKey();
     web::WebThread::PostTask(
-        web::WebThread::UI, FROM_HERE,
-        base::BindBlock(^{
+        web::WebThread::UI, FROM_HERE, base::BindBlockArc(^{
           [[CRWNetworkActivityIndicatorManager sharedInstance]
               clearNetworkTasksForGroup:networkActivityKey];
         }));