ServiceWorker: Resubmit worker script MIME type fix.

This is a re-submission of https://codereview.chromium.org/446323002/.
Fixed the new browsertest which intercept worker script request but returns
response without corret worker content type.

BUG=400604
TEST=https://codereview.chromium.org/448063002/

Review URL: https://codereview.chromium.org/460943002

Cr-Commit-Position: refs/heads/master@{#289238}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289238 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chrome_service_worker_browsertest.cc

@@ -49,6 +49,8 @@ static void ExpectResultAndRun(bool expected,
 IN_PROC_BROWSER_TEST_F(ChromeServiceWorkerTest,
                        CanShutDownWithRegisteredServiceWorker) {
   WriteFile(FILE_PATH_LITERAL("service_worker.js"), "");
+  WriteFile(FILE_PATH_LITERAL("service_worker.js.mock-http-headers"),
+            "HTTP/1.1 200 OK\nContent-Type: text/javascript");
 
   embedded_test_server()->ServeFilesFromDirectory(service_worker_dir_.path());
   ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());

content/browser/service_worker/service_worker_browsertest.cc

@@ -192,6 +192,7 @@ class LongLivedResourceInterceptor : public net::URLRequestInterceptor {
       net::NetworkDelegate* network_delegate) const OVERRIDE {
     const char kHeaders[] =
         "HTTP/1.1 200 OK\0"
+        "Content-Type: text/javascript\0"
         "Expires: Thu, 1 Jan 2100 20:00:00 GMT\0"
         "\0";
     std::string headers(kHeaders, arraysize(kHeaders));

content/browser/service_worker/service_worker_write_to_cache_job.cc

@@ -301,6 +301,18 @@ void ServiceWorkerWriteToCacheJob::OnResponseStarted(
     // response to our consumer, just don't cache it?
     return;
   }
+  // To prevent most user-uploaded content from being used as a serviceworker.
+  if (version_->script_url() == url_) {
+    std::string mime_type;
+    request->GetMimeType(&mime_type);
+    if (mime_type != "application/x-javascript" &&
+        mime_type != "text/javascript" &&
+        mime_type != "application/javascript") {
+      AsyncNotifyDoneHelper(net::URLRequestStatus(
+          net::URLRequestStatus::FAILED, net::ERR_FAILED));
+      return;
+    }
+  }
   WriteHeadersToCache();
 }
 

content/test/data/service_worker/fetch_event.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript

content/test/data/service_worker/fetch_event_reload.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript

content/test/data/service_worker/sync.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript

content/test/data/service_worker/worker.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript

content/test/data/service_worker/worker_activate_rejected.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript

content/test/data/service_worker/worker_install_fulfilled.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript

content/test/data/service_worker/worker_install_rejected.js.mock-http-headers

+HTTP/1.1 200 OK
+Content-Type: text/javascript