Prerender: Confirm ServiceWorkers are invoked for NoState Prefetch

chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc

Index: chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
diff --git a/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc b/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
index 6c1d72ff9bc201bdcb292665c6110df47712c3d7..786bcd854975fc8620a52fa6075b8fb99afc5bfa 100644
--- a/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
+++ b/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
@@ -20,6 +20,8 @@
 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/service_worker_context.h"
+#include "content/public/browser/storage_partition.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "net/base/escape.h"
@@ -33,6 +35,13 @@ using prerender::test_utils::DestructionWaiter;
 using prerender::test_utils::RequestCounter;
 using prerender::test_utils::TestPrerender;
 
+namespace {

[pasko, 2017/01/02 18:15:36]

nit: empty line after namespace for function declarations seems to be more
consistent with the rest of the code.

[mattcary, 2017/01/03 08:43:20]

Done.

+void ClosureOnUiThread(const base::Closure& callback) {
+  content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+                                   callback);
+}
+}  // namespace

[pasko, 2017/01/02 18:15:36]

nit: git grep -B 2 '}  // namespace$'

[mattcary, 2017/01/03 08:43:20]

Done.

+
 namespace prerender {
 
 // These URLs used for test resources must be relative with the exception of
@@ -49,6 +58,8 @@ const char kPrefetchResponseHeaderCSP[] =
     "prerender/prefetch_response_csp.html";
 const char kPrefetchScript[] = "prerender/prefetch.js";
 const char kPrefetchScript2[] = "prerender/prefetch2.js";
+const char kServiceWorkerLoader[] = "prerender/service_worker.html";
+const char kServiceWorkerJavascript[] = "prerender/service_worker.js";
 const char kPrefetchSubresourceRedirectPage[] =
     "prerender/prefetch_subresource_redirect.html";
 
@@ -514,4 +525,35 @@ IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, IssuesIdlePriorityRequests) {
   script_counter.WaitForCount(1);
 }
 
+// Checks that a registered ServiceWorker (SW) without a renderer intercepts a
+// prefetch request.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, ServiceWorkerIntercept) {
+  // Register and launch a SW.

[pasko, 2017/01/02 18:15:36]

Is it easy to add a similar test, but for the case when the SW is not registered
yet?

[mattcary, 2017/01/03 08:43:20]

Yes, in fact the other tests already do that (if prerender/service_worker.js,
prerender/prefetch.js would never be loaded).

+  RequestCounter sw_counter;
+  CountRequestFor(kServiceWorkerJavascript, &sw_counter);
+  ui_test_utils::NavigateToURL(
+      current_browser(),
+      src_server()->GetURL(MakeAbsolute(kServiceWorkerLoader)));
+  sw_counter.WaitForCount(1);
+
+  // Stop the SW renderer process.
+  base::RunLoop run_loop;
+  content::BrowserContext::GetStoragePartitionForSite(
+      GetActiveWebContents()->GetBrowserContext(),
+      src_server()->GetURL(MakeAbsolute(kPrefetchPng)))

[pasko, 2017/01/02 18:15:36]

nit: hard to count brackets, formatting does not help. A convenient point to
split I think would be 'storage_partition = '.

[mattcary, 2017/01/03 08:43:19]

Done.

+      ->GetServiceWorkerContext()
+      ->StopAllServiceWorkersForOriginWithCallback(
+          src_server()->GetURL("/"),
+          base::Bind(&ClosureOnUiThread, run_loop.QuitClosure()));

[pasko, 2017/01/02 18:15:36]

why not just run_loop.QuitClosure()? // i.e. without base::Bind and re-posting a
task

[mattcary, 2017/01/03 08:43:19]

The SW callback fires from the IO thread.

[pasko, 2017/01/03 13:09:14]

Thanks. I did not know that.

+  run_loop.Run();
+
+  // The SW intercepts kPrefetchPage and replaces it with a body that contains
+  // an <img> tage for kPrefetchPng. We verify that the SW ran correctly by

[pasko, 2017/01/02 18:15:36]

s/We verify/Verify/
(we prefer to avoid 'we' in comments)

[mattcary, 2017/01/03 08:43:20]

Done, although git grep -i ' we ' | grep cc | head.

+  // observing the fetch of the image.
+  RequestCounter image_counter;
+  CountRequestFor(kPrefetchPng, &image_counter);
+  PrefetchFromFile(kPrefetchPage, FINAL_STATUS_NOSTATE_PREFETCH_FINISHED);
+  image_counter.WaitForCount(1);
+}
+
 }  // namespace prerender