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 a14ad92b52bd494d7856eab917ba6c61e43d3f8b..0f98e188cbacfacfb2f7eaf94e49c03eeaeed363 100644
--- a/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
+++ b/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc
@@ -5,6 +5,7 @@
 #include "base/command_line.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_split.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/task_scheduler/post_task.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/history/history_test_utils.h"
@@ -20,6 +21,10 @@
 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/service_worker_context.h"
+#include "content/public/browser/storage_partition.h"

[falken, 2017/01/10 13:47:42]

I think lines 25-26 are no longer needed.

[mattcary, 2017/01/10 15:15:28]

Done.

+#include "content/public/common/result_codes.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "net/base/escape.h"
@@ -49,6 +54,7 @@ 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 kPrefetchSubresourceRedirectPage[] =
     "prerender/prefetch_subresource_redirect.html";
 
@@ -536,4 +542,42 @@ IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, IssuesIdlePriorityRequests) {
   script_counter.WaitForCount(1);
 }
 
+// Checks that a registered ServiceWorker (SW) that is not currently running
+// will intercepts a prefetch request.
+IN_PROC_BROWSER_TEST_F(NoStatePrefetchBrowserTest, ServiceWorkerIntercept) {
+  // Register and launch a SW.
+  base::string16 expected_title = base::ASCIIToUTF16("SW READY");
+  content::TitleWatcher title_watcher(GetActiveWebContents(), expected_title);
+  ui_test_utils::NavigateToURL(
+      current_browser(),
+      src_server()->GetURL(MakeAbsolute(kServiceWorkerLoader)));
+  EXPECT_EQ(expected_title, title_watcher.WaitAndGetTitle());
+
+  // Stop any SW.

[falken, 2017/01/10 13:47:42]

Could be worth mentioning that we're killing the render process in order to test
whether the renderer for prefetch interferes with SW startup, since otherwise
the SW would likely just start in the original render process.

[mattcary, 2017/01/10 15:15:28]

Done.

+  int host_count = 0;
+  for (content::RenderProcessHost::iterator iter(
+           content::RenderProcessHost::AllHostsIterator());
+       !iter.IsAtEnd(); iter.Advance()) {
+    ++host_count;
+    iter.GetCurrentValue()->Shutdown(content::RESULT_CODE_KILLED,
+                                     true /* wait */);
+  }
+  // There should be at most one render_process_host, that created for the SW.
+  EXPECT_EQ(1, host_count);
+
+  // Open a new tab to replace the one closed with all the RenderProcessHosts.

[clamy, 2017/01/10 14:42:53]

Note: if all the processes in a tab have been killed, you don't need to create a
new tab to have a new process. Just navigating to a url from the browser should
recreate a process for the tab.

That said if you really want to create a new tab, the function below should work
correctly.

[mattcary, 2017/01/10 15:15:28]

I would have thought that as well, but if I don't create a new tab, the test
hangs. I presume it's something to do with the in-process browser test setup,
but I couldn't confirm.

+  ui_test_utils::NavigateToURLWithDisposition(
+      current_browser(), GURL(url::kAboutBlankURL),
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+
+  // The SW intercepts kPrefetchPage and replaces it with a body that contains
+  // an <img> tage for kPrefetchPng. This verifies that the SW ran correctly by
+  // 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