With --site-per-process, avoid a crash when a subframe process goes away.

content/browser/site_per_process_browsertest.cc

Index: content/browser/site_per_process_browsertest.cc
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index 1523ec543d674def40af35ebff109ed8766a8ffc..a43dc6a3134b7fd38f68c330fac1d9239335fb94 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -161,16 +161,33 @@ void RedirectNotificationObserver::Observe(
 
 class SitePerProcessBrowserTest : public ContentBrowserTest {
  protected:
+  // Start at a data URL so each extra navigation creates a navigation entry.
+  // (The first navigation will silently be classified as AUTO_SUBFRAME.)
+  // TODO(creis): This won't be necessary when we can wait for LOAD_STOP.
+  void StartFrameAtDataURL() {
+    std::string data_url_script =
+      "var iframes = document.getElementById('test');iframes.src="
+      "'data:text/html,dataurl';";
+    ASSERT_TRUE(ExecuteScript(shell()->web_contents(), data_url_script));
+  }
+
   bool NavigateIframeToURL(Shell* window,
                            const GURL& url,
                            std::string iframe_id) {
+    // TODO(creis): This should wait for LOAD_STOP, but cross-site subframe
+    // navigations generate extra DidStartLoading and DidStopLoading messages.
+    // Until we replace swappedout:// with frame proxies, we need to listen for
+    // something else.  For now, we trigger NEW_SUBFRAME navigations and listen
+    // for commit.
     std::string script = base::StringPrintf(
-        "var iframes = document.getElementById('%s');iframes.src='%s';",
+        "setTimeout(\""
+        "var iframes = document.getElementById('%s');iframes.src='%s';"
+        "\",0)",
         iframe_id.c_str(), url.spec().c_str());
     WindowedNotificationObserver load_observer(
-        NOTIFICATION_LOAD_STOP,
+        NOTIFICATION_NAV_ENTRY_COMMITTED,
         Source<NavigationController>(
-            &shell()->web_contents()->GetController()));
+            &window->web_contents()->GetController()));
     bool result = ExecuteScript(window->web_contents(), script);
     load_observer.Wait();
     return result;
@@ -196,10 +213,15 @@ class SitePerProcessBrowserTest : public ContentBrowserTest {
 };
 
 // Ensure that we can complete a cross-process subframe navigation.
-// TODO(nasko): Disable this test for now, since enabling swapping out of
-// RenderFrameHosts causes this to break. Fix this test once
-// didFailProvisionalLoad is moved from RenderView to RenderFrame.
-IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, DISABLED_CrossSiteIframe) {
+// This is disabled on GTK due to a NOTREACHED in
+// RenderWidgetHostViewChildFrame::AllocBackingStore.  GTK support will be

[nasko, 2014/02/11 04:49:16]

This reminded me that I worked around this in my builds by specifying
--force-compositing-mode. I'm not sure if it will help here or if it worth
trying, since GTK is going away, so just mentioning it.

[Charlie Reis, 2014/02/12 00:27:57]

I'll give it a try in SetUpCommandLine.

+// removed before we support site-per-process.
+#if defined(TOOLKIT_GTK)
+#define MAYBE_CrossSiteIframe DISABLED_CrossSiteIframe
+#else
+#define MAYBE_CrossSiteIframe CrossSiteIframe
+#endif
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, MAYBE_CrossSiteIframe) {
   ASSERT_TRUE(test_server()->Start());
   net::SpawnedTestServer https_server(
       net::SpawnedTestServer::TYPE_HTTPS,
@@ -207,21 +229,22 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, DISABLED_CrossSiteIframe) {
       base::FilePath(FILE_PATH_LITERAL("content/test/data")));
   ASSERT_TRUE(https_server.Start());
   GURL main_url(test_server()->GetURL("files/site_per_process_main.html"));
-
   NavigateToURL(shell(), main_url);
 
+  StartFrameAtDataURL();
+
   SitePerProcessWebContentsObserver observer(shell()->web_contents());
 
   // Load same-site page into iframe.
   GURL http_url(test_server()->GetURL("files/title1.html"));
   EXPECT_TRUE(NavigateIframeToURL(shell(), http_url, "test"));
-  EXPECT_EQ(observer.navigation_url(), http_url);
+  EXPECT_EQ(http_url, observer.navigation_url());
   EXPECT_TRUE(observer.navigation_succeeded());
 
   // Load cross-site page into iframe.
   GURL https_url(https_server.GetURL("files/title1.html"));
   EXPECT_TRUE(NavigateIframeToURL(shell(), https_url, "test"));
-  EXPECT_EQ(observer.navigation_url(), https_url);
+  EXPECT_EQ(https_url, observer.navigation_url());
   EXPECT_TRUE(observer.navigation_succeeded());
 
   // Ensure that we have created a new process for the subframe.
@@ -238,6 +261,58 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, DISABLED_CrossSiteIframe) {
             child->current_frame_host()->GetProcess());
 }
 
+// Crash a subframe and ensures its children are cleared from the FrameTree.
+// See http://crbug.com/338508.
+#if defined(TOOLKIT_GTK)
+#define MAYBE_CrashSubframe DISABLED_CrashSubframe
+#else
+#define MAYBE_CrashSubframe CrashSubframe
+#endif
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, MAYBE_CrashSubframe) {
+  ASSERT_TRUE(test_server()->Start());
+  net::SpawnedTestServer https_server(
+      net::SpawnedTestServer::TYPE_HTTPS,
+      net::SpawnedTestServer::kLocalhost,
+      base::FilePath(FILE_PATH_LITERAL("content/test/data")));
+  ASSERT_TRUE(https_server.Start());
+  GURL main_url(test_server()->GetURL("files/site_per_process_main.html"));
+  NavigateToURL(shell(), main_url);
+
+  StartFrameAtDataURL();
+
+  // Load cross-site page into iframe.
+  GURL https_url(https_server.GetURL("files/title1.html"));
+  EXPECT_TRUE(NavigateIframeToURL(shell(), https_url, "test"));

[nasko, 2014/02/11 04:49:16]

This reminds me that it soon might be the time to look into providing generic
functions for navigating frames in the content test utils. I just need to move
ViewMsg_Navigate and it should be doable.

[Charlie Reis, 2014/02/12 00:27:57]

That will be great.

+
+  // Check the subframe process.
+  FrameTreeNode* root =
+      static_cast<WebContentsImpl*>(shell()->web_contents())->
+          GetFrameTree()->root();
+  ASSERT_EQ(1U, root->child_count());
+  FrameTreeNode* child = root->child_at(0);
+
+  // Crash the subframe process.
+  RenderProcessHost* root_process =
+      shell()->web_contents()->GetRenderProcessHost();

[nasko, 2014/02/11 04:49:16]

nit: Why not keep it consistent with the next line and use
root->current_frame_host()->GetProcess()?

[Charlie Reis, 2014/02/12 00:27:57]

Done.

+  RenderProcessHost* child_process = child->current_frame_host()->GetProcess();
+  RenderProcessHostWatcher crash_observer(
+      child_process,
+      RenderProcessHostWatcher::WATCH_FOR_PROCESS_EXIT);
+  base::KillProcess(child_process->GetHandle(), 0, false);
+  crash_observer.Wait();
+
+  // Ensure that the child frame still exists but has been cleared.

[nasko, 2014/02/11 04:49:16]

nit: How are we testing that it is cleared?

[Charlie Reis, 2014/02/12 00:27:57]

Heh, I started with some lines to check that the URL was gone, but I discovered
we have a separate bug in putting the URL on the wrong node (thanks to frame
ID).  I figured I'd fix that bug later.

I've put in a check for the frame_id getting cleared for now.  This will all get
updated in my frame_id CL.

+  EXPECT_EQ(1U, root->child_count());
+
+  // Now crash the top-level page to clear the child frame.
+  RenderProcessHostWatcher crash_observer2(

[nasko, 2014/02/11 04:49:16]

nit: Why not add local scope to avoid having variable(1|2)?

[Charlie Reis, 2014/02/12 00:27:57]

Done.

+      root_process,
+      RenderProcessHostWatcher::WATCH_FOR_PROCESS_EXIT);
+  base::KillProcess(root_process->GetHandle(), 0, false);
+  crash_observer2.Wait();
+  EXPECT_EQ(0U, root->child_count());
+}
+
 // TODO(nasko): Disable this test until out-of-process iframes is ready and the
 // security checks are back in place.
 IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,