Revert "Remove cors:: namespace specifier in the namespace"

This reverts commit 0af66703.

Reason for revert: Suspected of causing check failures across a variety of tests on the Android CFI bot. See https://crbug.com/881538 for more details.

Original change's description:
> Remove cors:: namespace specifier in the namespace
> 
> Bug: None
> Cq-Include-Trybots: luci.chromium.try:linux_mojo
> Change-Id: Ib487fee40beaac941b74c090d31133b12d61ea4a
> Reviewed-on: https://chromium-review.googlesource.com/1203517
> Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
> Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#589158}

TBR=toyoshim@chromium.org,yhirano@chromium.org

Change-Id: I1f7065dbeb733c4378babfba36236f2467073a5f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 881538
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Reviewed-on: https://chromium-review.googlesource.com/1211949Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Commit-Queue: Justin Donnelly <jdonnelly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589315}

services/network/cors/cors_url_loader.cc

@@ -27,7 +27,7 @@ base::Optional<std::string> GetHeaderString(
 }
 
 bool NeedsPreflight(const ResourceRequest& request) {
-  if (!IsCORSEnabledRequestMode(request.fetch_request_mode))
+  if (!cors::IsCORSEnabledRequestMode(request.fetch_request_mode))
     return false;
 
   if (request.is_external_request)
@@ -88,7 +88,7 @@ CORSURLLoader::~CORSURLLoader() = default;
 
 void CORSURLLoader::Start() {
   if (fetch_cors_flag_ &&
-      IsCORSEnabledRequestMode(request_.fetch_request_mode)) {
+      cors::IsCORSEnabledRequestMode(request_.fetch_request_mode)) {
     // Username and password should be stripped in a CORS-enabled request.
     if (request_.url.has_username() || request_.url.has_password()) {
       GURL::Replacements replacements;

services/network/cors/preflight_controller.cc

@@ -81,18 +81,18 @@ std::unique_ptr<ResourceRequest> CreatePreflightRequest(
   preflight_request->load_flags |= net::LOAD_DO_NOT_SEND_AUTH_DATA;
 
   preflight_request->headers.SetHeader(
-      header_names::kAccessControlRequestMethod, request.method);
+      cors::header_names::kAccessControlRequestMethod, request.method);
 
   std::string request_headers =
       CreateAccessControlRequestHeadersHeader(request.headers);
   if (!request_headers.empty()) {
     preflight_request->headers.SetHeader(
-        header_names::kAccessControlRequestHeaders, request_headers);
+        cors::header_names::kAccessControlRequestHeaders, request_headers);
   }
 
   if (request.is_external_request) {
     preflight_request->headers.SetHeader(
-        header_names::kAccessControlRequestExternal, "true");
+        cors::header_names::kAccessControlRequestExternal, "true");
   }
 
   DCHECK(request.request_initiator);
@@ -123,9 +123,10 @@ std::unique_ptr<PreflightResult> CreatePreflightResult(
   // TODO(toyoshim): Reflect --allow-file-access-from-files flag.
   *detected_error_status = CheckPreflightAccess(
       final_url, head.headers->response_code(),
-      GetHeaderString(head.headers, header_names::kAccessControlAllowOrigin),
       GetHeaderString(head.headers,
-                      header_names::kAccessControlAllowCredentials),
+                      cors::header_names::kAccessControlAllowOrigin),
+      GetHeaderString(head.headers,
+                      cors::header_names::kAccessControlAllowCredentials),
       original_request.fetch_credentials_mode,
       tainted ? url::Origin() : *original_request.request_initiator,
       false /* allow_file_origin */);

services/network/cors/preflight_controller_unittest.cc

@@ -50,7 +50,7 @@ TEST(PreflightControllerCreatePreflightRequestTest, LexicographicalOrder) {
   EXPECT_EQ("null", header);
 
   EXPECT_TRUE(preflight->headers.GetHeader(
-      header_names::kAccessControlRequestHeaders, &header));
+      cors::header_names::kAccessControlRequestHeaders, &header));
   EXPECT_EQ("apple,content-type,kiwifruit,orange,strawberry", header);
 }
 
@@ -73,7 +73,7 @@ TEST(PreflightControllerCreatePreflightRequestTest, ExcludeSimpleHeaders) {
   // left out in the preflight request.
   std::string header;
   EXPECT_FALSE(preflight->headers.GetHeader(
-      header_names::kAccessControlRequestHeaders, &header));
+      cors::header_names::kAccessControlRequestHeaders, &header));
 }
 
 TEST(PreflightControllerCreatePreflightRequestTest, Credentials) {
@@ -108,7 +108,7 @@ TEST(PreflightControllerCreatePreflightRequestTest,
   // Empty list also; see comment in test above.
   std::string header;
   EXPECT_FALSE(preflight->headers.GetHeader(
-      header_names::kAccessControlRequestHeaders, &header));
+      cors::header_names::kAccessControlRequestHeaders, &header));
 }
 
 TEST(PreflightControllerCreatePreflightRequestTest, IncludeNonSimpleHeader) {
@@ -123,7 +123,7 @@ TEST(PreflightControllerCreatePreflightRequestTest, IncludeNonSimpleHeader) {
 
   std::string header;
   EXPECT_TRUE(preflight->headers.GetHeader(
-      header_names::kAccessControlRequestHeaders, &header));
+      cors::header_names::kAccessControlRequestHeaders, &header));
   EXPECT_EQ("x-custom-header", header);
 }
 
@@ -141,7 +141,7 @@ TEST(PreflightControllerCreatePreflightRequestTest,
 
   std::string header;
   EXPECT_TRUE(preflight->headers.GetHeader(
-      header_names::kAccessControlRequestHeaders, &header));
+      cors::header_names::kAccessControlRequestHeaders, &header));
   EXPECT_EQ("content-type", header);
 }
 
@@ -157,7 +157,7 @@ TEST(PreflightControllerCreatePreflightRequestTest, ExcludeForbiddenHeaders) {
 
   std::string header;
   EXPECT_FALSE(preflight->headers.GetHeader(
-      header_names::kAccessControlRequestHeaders, &header));
+      cors::header_names::kAccessControlRequestHeaders, &header));
 }
 
 TEST(PreflightControllerCreatePreflightRequestTest, Tainted) {
@@ -256,7 +256,7 @@ class PreflightControllerTest : public testing::Test {
           net::test_server::ShouldHandle(request, "/tainted")
               ? url::Origin()
               : url::Origin::Create(test_server_.base_url());
-      response->AddCustomHeader(header_names::kAccessControlAllowOrigin,
+      response->AddCustomHeader(cors::header_names::kAccessControlAllowOrigin,
                                 origin.Serialize());
       response->AddCustomHeader(header_names::kAccessControlAllowMethods,
                                 "GET, OPTIONS");