Make prerender code use two argument ResponseHeader manipulation calls

We want to get rid of the single argument AddHeader() method as the two
argument AddHeader() and SetHeader() methods are safer and more flexible.

Bug: 1068194
Change-Id: I378a1d1252d29b53cc5f49cc8d54eb29e126fed1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2149630
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Auto-Submit: Matt Menke <mmenke@chromium.org>
Reviewed-by: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759013}

chrome/browser/prerender/isolated/isolated_prerender_tab_helper_unittest.cc

@@ -208,10 +208,11 @@ class IsolatedPrerenderTabHelperTest : public ChromeRenderViewHostTestHarness {
     return std::string();
   }
 
-  void MakeResponseAndWait(net::HttpStatusCode http_status,
+  void MakeResponseAndWait(
+      net::HttpStatusCode http_status,
       net::Error net_error,
       const std::string& mime_type,
-                           std::vector<std::string> headers,
+      std::vector<std::pair<std::string, std::string>> headers,
       const std::string& body) {
     network::TestURLLoaderFactory::PendingRequest* request =
         test_url_loader_factory_.GetPendingRequest(0);
@@ -230,8 +231,8 @@ class IsolatedPrerenderTabHelperTest : public ChromeRenderViewHostTestHarness {
         base::TimeDelta::FromMilliseconds(kConnectTimeDuration);
 
     head->mime_type = mime_type;
-    for (const std::string& header : headers) {
-      head->headers->AddHeader(header);
+    for (const auto& header : headers) {
+      head->headers->AddHeader(header.first, header.second);
     }
     network::URLLoaderCompletionStatus status(net_error);
     test_url_loader_factory_.AddResponse(request->request.url, std::move(head),
@@ -733,7 +734,7 @@ TEST_F(IsolatedPrerenderTabHelperTest, SuccessCase) {
 
   network::ResourceRequest request = VerifyCommonRequestState(prediction_url);
   MakeResponseAndWait(net::HTTP_OK, net::OK, kHTMLMimeType,
-                      {"X-Testing: Hello World"}, kHTMLBody);
+                      {{"X-Testing", "Hello World"}}, kHTMLBody);
 
   std::unique_ptr<PrefetchedMainframeResponseContainer> resp =
       tab_helper()->TakePrefetchResponse(prediction_url);
@@ -1165,9 +1166,10 @@ class IsolatedPrerenderTabHelperRedirectTest
     ClearResponses();
   }
 
-  void MakeFinalResponse(const GURL& final_url,
+  void MakeFinalResponse(
+      const GURL& final_url,
       net::HttpStatusCode final_status,
-                         std::vector<std::string> final_headers,
+      std::vector<std::pair<std::string, std::string>> final_headers,
       const std::string& final_body) {
     auto final_head = network::CreateURLResponseHead(final_status);
 
@@ -1184,8 +1186,8 @@ class IsolatedPrerenderTabHelperRedirectTest
 
     final_head->mime_type = kHTMLMimeType;
 
-    for (const std::string& header : final_headers) {
-      final_head->headers->AddHeader(header);
+    for (const auto& header : final_headers) {
+      final_head->headers->AddHeader(header.first, header.second);
     }
     network::TestURLLoaderFactory::PendingRequest* request =
         test_url_loader_factory_.GetPendingRequest(0);
@@ -1279,7 +1281,7 @@ TEST_F(IsolatedPrerenderTabHelperRedirectTest, SuccessfulRedirect) {
   VerifyCommonRequestState(prediction_url);
 
   WalkRedirectChainUntilFinalRequest({prediction_url, redirect_url});
-  MakeFinalResponse(redirect_url, net::HTTP_OK, {"X-Testing: Hello World"},
+  MakeFinalResponse(redirect_url, net::HTTP_OK, {{"X-Testing", "Hello World"}},
                     kHTMLBody);
 
   std::unique_ptr<PrefetchedMainframeResponseContainer> resp =