Cancel prerender when we discover a download starting from a page we are prerendering.

BUG=71214
TEST=Search for carbon poker download and wait. The first result, which has a <link rel="prefetch"> will not cause a prerender as the download that the next page starts will cancel it.


Review URL: http://codereview.chromium.org/6459005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@75168 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 47 insertions, 2 deletions

diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index 6088650..18710a0 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -114,7 +114,6 @@ class PrerenderBrowserTest : public InProcessBrowserTest {
                         FinalStatus expected_final_status,
                         int total_navigations) {
     ASSERT_TRUE(test_server()->Start());
-
     std::string src_path = "files/prerender/prerender_loader.html?";
     src_path.append(html_file);
     std::string dest_path = "files/prerender/";
@@ -249,6 +248,28 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderRedirect) {
   NavigateToDestURL();
 }
 
+// Prerenders a page that contains an automatic download triggered through an
+// iframe. This should not prerender successfully.
+IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderDownloadIFrame) {
+  PrerenderTestURL("prerender_download_iframe.html",
+                   FINAL_STATUS_DOWNLOAD, 1);
+}
+
+// Prerenders a page that contains an automatic download triggered through
+// Javascript changing the window.location. This should not prerender
+// successfully.
+IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderDownloadLocation) {
+  PrerenderTestURL("prerender_download_location.html",
+                   FINAL_STATUS_DOWNLOAD, 2);
+}
+
+// Prerenders a page that contains an automatic download triggered through a
+// <meta http-equiv="refresh"> tag. This should not prerender successfully.
+IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderDownloadRefresh) {
+  PrerenderTestURL("prerender_download_refresh.html",
+                   FINAL_STATUS_DOWNLOAD, 2);
+}
+
 // Checks that the referrer is set when prerendering.
 IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderReferrer) {
   PrerenderTestURL("prerender_referrer.html",
diff --git a/chrome/browser/prerender/prerender_contents.cc b/chrome/browser/prerender/prerender_contents.cc
index a5d7975..7428b0e 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -87,6 +87,10 @@ void PrerenderContents::StartPrerendering() {
   registrar_.Add(this, NotificationType::AUTH_CANCELLED,
                  NotificationService::AllSources());
 
+  // Register all responses to see if we should cancel.
+  registrar_.Add(this, NotificationType::DOWNLOAD_INITIATED,
+                 NotificationService::AllSources());
+
   DCHECK(load_start_time_.is_null());
   load_start_time_ = base::TimeTicks::Now();
 
@@ -101,6 +105,7 @@ void PrerenderContents::StartPrerendering() {
 void PrerenderContents::set_final_status(FinalStatus final_status) {
   DCHECK(final_status >= FINAL_STATUS_USED && final_status < FINAL_STATUS_MAX);
   DCHECK_EQ(FINAL_STATUS_MAX, final_status_);
+
   final_status_ = final_status;
 }
 
@@ -190,6 +195,7 @@ void PrerenderContents::Observe(NotificationType type,
     case NotificationType::PROFILE_DESTROYED:
       Destroy(FINAL_STATUS_PROFILE_DESTROYED);
       return;
+
     case NotificationType::APP_TERMINATING:
       Destroy(FINAL_STATUS_APP_TERMINATING);
       return;
@@ -205,8 +211,25 @@ void PrerenderContents::Observe(NotificationType type,
       LoginHandler* handler = details_ptr->handler();
       DCHECK(handler != NULL);
       RenderViewHostDelegate* delegate = handler->GetRenderViewHostDelegate();
-      if (controller == NULL && delegate == this)
+      if (controller == NULL && delegate == this) {
         Destroy(FINAL_STATUS_AUTH_NEEDED);
+        return;
+      }
+      break;
+    }
+
+    case NotificationType::DOWNLOAD_INITIATED: {
+      // If the download is started from a RenderViewHost that we are
+      // delegating, kill the prerender. This cancels any pending requests
+      // though the download never actually started thanks to the
+      // DownloadRequestLimiter.
+      DCHECK(NotificationService::NoDetails() == details);
+      RenderViewHost* rvh = Source<RenderViewHost>(source).ptr();
+      CHECK(rvh != NULL);
+      if (rvh->delegate() == this) {
+        Destroy(FINAL_STATUS_DOWNLOAD);
+        return;
+      }
       break;
     }
 
diff --git a/chrome/browser/prerender/prerender_final_status.h b/chrome/browser/prerender/prerender_final_status.h
index ab90f03..fba235c 100644
--- a/chrome/browser/prerender/prerender_final_status.h
+++ b/chrome/browser/prerender/prerender_final_status.h
@@ -21,6 +21,7 @@ enum FinalStatus {
   FINAL_STATUS_JAVASCRIPT_ALERT,
   FINAL_STATUS_AUTH_NEEDED,
   FINAL_STATUS_HTTPS,
+  FINAL_STATUS_DOWNLOAD,
   FINAL_STATUS_MAX,
 };