Make RenderFrameHostManager swap RenderFrameHosts, not RenderViewHosts.

content/browser/renderer_host/render_view_host_browsertest.cc

Index: content/browser/renderer_host/render_view_host_browsertest.cc
diff --git a/content/browser/renderer_host/render_view_host_browsertest.cc b/content/browser/renderer_host/render_view_host_browsertest.cc
index 386ff521afb540d78f8178688d01a4226f2cfc5f..555852c01d6da45316ec5bdb324302ca860ec7b4 100644
--- a/content/browser/renderer_host/render_view_host_browsertest.cc
+++ b/content/browser/renderer_host/render_view_host_browsertest.cc
@@ -6,6 +6,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "base/values.h"
+#include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/view_messages.h"
@@ -100,19 +101,19 @@ IN_PROC_BROWSER_TEST_F(RenderViewHostTest, BasicRenderFrameHost) {
   GURL test_url = embedded_test_server()->GetURL("/simple_page.html");
   NavigateToURL(shell(), test_url);
 
-  RenderViewHostImpl* rvh = static_cast<RenderViewHostImpl*>(
-      shell()->web_contents()->GetRenderViewHost());
-  EXPECT_TRUE(rvh->main_render_frame_host());
+  FrameTreeNode* old_root = static_cast<WebContentsImpl*>(
+      shell()->web_contents())->GetFrameTree()->root();
+  EXPECT_TRUE(old_root->current_frame_host());
 
   ShellAddedObserver new_shell_observer;
   EXPECT_TRUE(ExecuteScript(shell()->web_contents(), "window.open();"));
   Shell* new_shell = new_shell_observer.GetShell();
-  RenderViewHostImpl* new_rvh = static_cast<RenderViewHostImpl*>(
-      new_shell->web_contents()->GetRenderViewHost());
+  FrameTreeNode* new_root = static_cast<WebContentsImpl*>(
+      new_shell->web_contents())->GetFrameTree()->root();
 
-  EXPECT_TRUE(new_rvh->main_render_frame_host());
-  EXPECT_NE(rvh->main_render_frame_host()->routing_id(),
-            new_rvh->main_render_frame_host()->routing_id());
+  EXPECT_TRUE(new_root->current_frame_host());
+  EXPECT_NE(old_root->current_frame_host()->routing_id(),
+            new_root->current_frame_host()->routing_id());
 }
 
 }  // namespace content