Enable resource prefetch from the browser process.

chrome/browser/prefetch/prefetch_browsertest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
+#include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
+#include "chrome/common/prefetch_messages.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/test/browser_test_utils.h"
+#include "net/url_request/url_request_filter.h"
+#include "net/url_request/url_request_job.h"
+
+using content::BrowserThread;
 
 namespace {
 
 const char kPrefetchPage[] = "files/prerender/simple_prefetch.html";
 
 class PrefetchBrowserTestBase : public InProcessBrowserTest {
  public:
   explicit PrefetchBrowserTestBase(bool do_predictive_networking,
                                    bool do_prefetch_field_trial)
       : do_predictive_networking_(do_predictive_networking),
@@ skipping 51 matching lines @@
   PrefetchBrowserTestPredictionOffExpOn()
       : PrefetchBrowserTestBase(false, true) {}
 };
 
 class PrefetchBrowserTestPredictionOffExpOff : public PrefetchBrowserTestBase {
  public:
   PrefetchBrowserTestPredictionOffExpOff()
       : PrefetchBrowserTestBase(false, false) {}
 };
 
+// URLRequestJob (and associated handler) which hangs.
+class HangingURLRequestJob : public net::URLRequestJob {
+ public:
+  HangingURLRequestJob(net::URLRequest* request,
+                          net::NetworkDelegate* network_delegate)
+      : net::URLRequestJob(request, network_delegate) {
+  }
+
+  virtual void Start() OVERRIDE {}
+
+ private:
+  virtual ~HangingURLRequestJob() {}
+};
+
+class HangingRequestInterceptor : public net::URLRequestInterceptor {
+ public:
+  explicit HangingRequestInterceptor(base::Closure callback)
+      : callback_(callback) {
+  }
+
+  virtual ~HangingRequestInterceptor() {}
+
+  virtual net::URLRequestJob* MaybeInterceptRequest(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const OVERRIDE {
+    if (!callback_.is_null()) {
+      BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, callback_);
+    }
+    return new HangingURLRequestJob(request, network_delegate);
+  }
+
+ private:
+  base::Closure callback_;
+};
+
+void CreateHangingRequestInterceptorOnIO(const GURL& url,
+                                         base::Closure callback) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  scoped_ptr<net::URLRequestInterceptor> never_respond_handler(
+      new HangingRequestInterceptor(callback));
+  net::URLRequestFilter::GetInstance()->AddUrlInterceptor(
+      url, never_respond_handler.Pass());
+}
+
 // Privacy option is on, experiment is on.  Prefetch should succeed.
 IN_PROC_BROWSER_TEST_F(PrefetchBrowserTestPredictionOnExpOn, PredOnExpOn) {
   EXPECT_TRUE(RunPrefetchExperiment(true, browser()));
 }
 
 // Privacy option is on, experiment is off.  Prefetch should be dropped.
 IN_PROC_BROWSER_TEST_F(PrefetchBrowserTestPredictionOnExpOff, PredOnExpOff) {
   EXPECT_TRUE(RunPrefetchExperiment(false, browser()));
 }
 
@@ skipping 14 matching lines @@
   Browser* incognito_browser = new Browser(
       Browser::CreateParams(incognito_profile, browser()->host_desktop_type()));
 
   // Navigate just to have a tab in this window, otherwise there is no
   // WebContents for the incognito browser.
   ui_test_utils::OpenURLOffTheRecord(browser()->profile(), GURL("about:blank"));
 
   EXPECT_TRUE(RunPrefetchExperiment(true, incognito_browser));
 }
 
+IN_PROC_BROWSER_TEST_F(PrefetchBrowserTestPredictionOnExpOn,
+                       PrefetchFromBrowser) {
+  const GURL kHangingUrl("http://hanging-url.com");
+  base::RunLoop loop_;
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&CreateHangingRequestInterceptorOnIO,
+                 kHangingUrl,
+                 loop_.QuitClosure()));
+  ui_test_utils::NavigateToURL(browser(), GURL("about:blank"));
+  content::RenderFrameHost* rfh =
+      browser()->tab_strip_model()->GetActiveWebContents()->GetMainFrame();
+  rfh->Send(new PrefetchMsg_Prefetch(rfh->GetRoutingID(), kHangingUrl));
+  loop_.Run();

[jkarlin, 2014/06/16 14:48:29]

What is this test testing exactly?

[tburkard, 2014/06/16 15:02:57]

Done.

added a comment explaining

+}
+
 }  // namespace
-