Use Chrome User Agent for download requests.

Some web sites return HTML page instead of PassKit object if request's
User Agent is not a known iOS browser.

Bug: 806759
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I566fe85eadb889dd715ddf858b07b6cef4a736c5
Reviewed-on: https://chromium-review.googlesource.com/891760Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532893}

ios/web/download/download_controller_impl.mm

@@ -7,7 +7,9 @@
 #include "base/strings/sys_string_conversions.h"
 #include "ios/web/public/browser_state.h"
 #import "ios/web/public/download/download_controller_delegate.h"
+#import "ios/web/public/web_client.h"
 #import "net/base/mac/url_conversions.h"
+#include "net/http/http_request_headers.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -86,6 +88,13 @@ NSURLSession* DownloadControllerImpl::CreateSession(
     NSOperationQueue* delegate_queue) {
   NSURLSessionConfiguration* configuration = [NSURLSessionConfiguration
       backgroundSessionConfigurationWithIdentifier:identifier];
+
+  std::string user_agent = GetWebClient()->GetUserAgent(UserAgentType::MOBILE);
+  configuration.HTTPAdditionalHeaders = @{
+    base::SysUTF8ToNSString(net::HttpRequestHeaders::kUserAgent) :
+        base::SysUTF8ToNSString(user_agent),
+  };
+
   return [NSURLSession sessionWithConfiguration:configuration
                                        delegate:delegate
                                   delegateQueue:delegate_queue];

ios/web/download/download_inttest.mm

@@ -12,8 +12,11 @@
 #import "ios/web/public/navigation_manager.h"
 #include "ios/web/public/test/fakes/fake_download_controller_delegate.h"
 #import "ios/web/public/test/web_test_with_web_state.h"
+#import "ios/web/public/web_client.h"
 #import "ios/web/public/web_state/web_state.h"
+#include "net/http/http_request_headers.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
+#include "net/test/embedded_test_server/http_request.h"
 #include "net/test/embedded_test_server/http_response.h"
 #include "net/url_request/url_fetcher_response_writer.h"
 
@@ -35,10 +38,15 @@ const char kContent[] = "testdata";
 std::unique_ptr<net::test_server::HttpResponse> GetDownloadResponse(
     const net::test_server::HttpRequest& request) {
   auto result = std::make_unique<net::test_server::BasicHttpResponse>();
-  result->set_code(net::HTTP_OK);
-  result->set_content(kContent);
-  result->AddCustomHeader("Content-Type", kMimeType);
-  result->AddCustomHeader("Content-Disposition", kContentDisposition);
+
+  std::string user_agent =
+      request.headers.at(net::HttpRequestHeaders::kUserAgent);
+  if (user_agent == GetWebClient()->GetUserAgent(UserAgentType::MOBILE)) {
+    result->set_code(net::HTTP_OK);
+    result->set_content(kContent);
+    result->AddCustomHeader("Content-Type", kMimeType);
+    result->AddCustomHeader("Content-Disposition", kContentDisposition);
+  }
   return result;
 }
 

ios/web/public/test/fakes/test_web_client.h

@@ -27,6 +27,7 @@ class TestWebClient : public web::WebClient {
   void AddAdditionalSchemes(Schemes* schemes) const override;
   // Returns true for kTestWebUIScheme and kTestNativeContentScheme URL schemes.
   bool IsAppSpecificURL(const GURL& url) const override;
+  std::string GetUserAgent(UserAgentType type) const override;
   base::RefCountedMemory* GetDataResourceBytes(int id) const override;
   NSString* GetDocumentStartScriptForMainFrame(
       BrowserState* browser_state) const override;

ios/web/public/test/fakes/test_web_client.mm

@@ -31,6 +31,10 @@ bool TestWebClient::IsAppSpecificURL(const GURL& url) const {
          url.SchemeIs(kTestNativeContentScheme);
 }
 
+std::string TestWebClient::GetUserAgent(UserAgentType type) const {
+  return "Chromium/66.0.3333.0 CFNetwork/893.14 Darwin/16.7.0";
+}
+
 base::RefCountedMemory* TestWebClient::GetDataResourceBytes(
     int resource_id) const {
   if (!ui::ResourceBundle::HasSharedInstance())