Ensure we properly set PageTransition for iframes.

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 3e76965f11b08874ebf072342ca576b0cec29ad1..a6353959c1adca4f307aa4d5a81252efbf2082e5 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -18,6 +18,7 @@
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/frame_messages.h"
+#include "content/public/browser/navigation_details.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
@@ -2044,4 +2045,33 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, RFPHDestruction) {
       DepictFrameTree(root));
 }
 
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
+                       PageTransitionForSecondaryIframeNavigation) {
+  GURL main_url(embedded_test_server()->GetURL("/site_per_process_main.html"));
+  NavigateToURL(shell(), main_url);
+
+  // It is safe to obtain the root frame tree node here, as it doesn't change.
+  FrameTreeNode* root =
+      static_cast<WebContentsImpl*>(shell()->web_contents())->
+          GetFrameTree()->root();
+
+  TestNavigationObserver observer(shell()->web_contents());
+
+  // Load same-site page into iframe.
+  FrameTreeNode* child = root->child_at(0);
+  GURL http_url(embedded_test_server()->GetURL("/title1.html"));
+  NavigateFrameToURL(child, http_url);
+  EXPECT_EQ(http_url, observer.last_navigation_url());
+  EXPECT_TRUE(observer.last_navigation_succeeded());
+
+  // Load cross-site page into iframe.
+  TestFrameNavigationObserver frame_observer(child, 1);
+  GURL url = embedded_test_server()->GetURL("foo.com", "/title2.html");
+  NavigateIframeToURL(shell()->web_contents(), "test", url);
+  frame_observer.Wait();
+
+  EXPECT_EQ(NAVIGATION_TYPE_NEW_SUBFRAME,
+            frame_observer.load_committed_details().type);
+}
+
 }  // namespace content