Adds a test that verifies that navigating in the unload handler while

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 ea4bb0da5c3fc3c61f87442773244420a49bf876..9f6363a2a82fe708ff92079c0c4935832adcf8f5 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -7920,4 +7920,68 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
   EXPECT_TRUE(ExecuteScript(popup_shell->web_contents(), "true"));
 }
 
+// Tests that trying to navigate in the unload handler doesn't crash the
+// browser.
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, NavigateInUnloadHandler) {
+  GURL main_url(embedded_test_server()->GetURL(
+      "a.com", "/cross_site_iframe_factory.html?a(b(b))"));
+  NavigateToURL(shell(), main_url);
+
+  FrameTreeNode* root = static_cast<WebContentsImpl*>(shell()->web_contents())
+                            ->GetFrameTree()
+                            ->root();
+
+  EXPECT_EQ(
+      " Site A ------------ proxies for B\n"
+      "   +--Site B ------- proxies for A\n"
+      "        +--Site B -- proxies for A\n"
+      "Where A = http://a.com/\n"
+      "      B = http://b.com/",
+      DepictFrameTree(root));
+
+  int child_count = 0;
+  EXPECT_TRUE(ExecuteScriptAndExtractInt(
+      root->child_at(0)->current_frame_host(),
+      "window.domAutomationController.send(frames.length);", &child_count));
+  EXPECT_EQ(1, child_count);
+
+  // Add an unload handler to B's subframe.
+  EXPECT_TRUE(
+      ExecuteScript(root->child_at(0)->child_at(0)->current_frame_host(),
+                    "window.onunload=function(e){\n"
+                    "    window.location = '#navigate';\n"
+                    "};\n"));
+
+  // Navigate B's subframe to a cross-site C.
+  std::string script =
+      std::string("window.document.getElementById('child-0').src = \"") +
+      embedded_test_server()
+          ->GetURL("c.com", "/cross_site_iframe_factory.html")
+          .spec() +
+      "\"";
+  EXPECT_TRUE(
+      ExecuteScript(root->child_at(0)->current_frame_host(), script.c_str()));
+
+  // Wait until B's subframe RenderFrameHost is destroyed.
+  RenderFrameDeletedObserver deleted_observer(
+      root->child_at(0)->child_at(0)->current_frame_host());
+  deleted_observer.WaitUntilDeleted();
+
+  // Check that C's subframe is alive and the navigation in the unload handler
+  // was ignored.
+  EXPECT_TRUE(ExecuteScriptAndExtractInt(
+      root->child_at(0)->child_at(0)->current_frame_host(),
+      "window.domAutomationController.send(frames.length);", &child_count));
+  EXPECT_EQ(0, child_count);
+
+  EXPECT_EQ(
+      " Site A ------------ proxies for B C\n"
+      "   +--Site B ------- proxies for A C\n"
+      "        +--Site C -- proxies for A B\n"
+      "Where A = http://a.com/\n"
+      "      B = http://b.com/\n"
+      "      C = http://c.com/",
+      DepictFrameTree(root));
+}
+
 }  // namespace content