Set the Accept-Language header in Physical Web requests

ios/chrome/common/physical_web/physical_web_request.mm

 // Copyright 2015 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/common/physical_web/physical_web_request.h"
 
 #include "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_block.h"
@@ skipping 86 matching lines @@
   // body of the POST request.
   NSDictionary* jsonBody =
       @{ kUrlsKey : @[ @{kUrlKey : [[device_ url] absoluteString]} ] };
   [request_ setHTTPBody:[NSJSONSerialization dataWithJSONObject:jsonBody
                                                         options:0
                                                           error:NULL]];
   [request_ setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
   [request_ setValue:base::SysUTF8ToNSString(GetUserAgent())
       forHTTPHeaderField:@"User-Agent"];
 
+  // Set the Accept-Language header from the locale language code. This may
+  // cause us to fetch metadata for the wrong region in languages such as
+  // Chinese that vary significantly between regions.
+  // TODO(mattreynolds): Use the same Accept-Language string as WKWebView.
+  NSString* acceptLanguage =
+      [[NSLocale currentLocale] objectForKey:NSLocaleLanguageCode];
+  [request_ setValue:acceptLanguage forHTTPHeaderField:@"Acccept-Language"];
+
   startDate_.reset([[NSDate date] retain]);
   // Starts the request.
   NSURLSession* session =
       [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration
                                                  ephemeralSessionConfiguration]
                                     delegate:nil
                                delegateQueue:[NSOperationQueue mainQueue]];
   base::WeakNSObject<PhysicalWebRequest> weakSelf(self);
   SessionCompletionProceduralBlock completionHandler =
       ^(NSData* data, NSURLResponse* response, NSError* error) {
@@ skipping 121 matching lines @@
         transmitPower:[device_ transmitPower]
                  rssi:[device_ rssi]
                  rank:physical_web::kMaxRank]);
     if (block_.get() != nil) {
       block_.get()(device, nil);
     }
   }
 }
 
 @end