Destroy the old RenderWidgetHostView when swapping out a main frame.

chrome/browser/search/search_unittest.cc

Index: chrome/browser/search/search_unittest.cc
diff --git a/chrome/browser/search/search_unittest.cc b/chrome/browser/search/search_unittest.cc
index 1761130c99d8e1926462d9ce02a00d2dac8b94d9..4c0ba0b1c053cda37045ee94d2683809fc788a7a 100644
--- a/chrome/browser/search/search_unittest.cc
+++ b/chrome/browser/search/search_unittest.cc
@@ -44,6 +44,10 @@
 #include "chrome/browser/supervised_user/supervised_user_url_filter.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
+#endif
+
 namespace search {
 
 class SearchTest : public BrowserWithTestWindowTest {
@@ -58,6 +62,18 @@ class SearchTest : public BrowserWithTestWindowTest {
         TemplateURLServiceFactory::GetForProfile(profile());
     search_test_utils::WaitForTemplateURLServiceToLoad(template_url_service);
     SetSearchProvider(true, false);
+
+#if defined(OS_MACOSX)
+  ui::WindowResizeHelperMac::Get()->Init(base::ThreadTaskRunnerHandle::Get());

[Charlie Reis, 2016/11/23 07:25:22]

Just for the record, what made this test change necessary?

[lfg, 2016/11/29 17:41:22]

Search test performs multiple navigations, in particular, look at
kInstantNTPTestCases, where it navigates to foo.com, then bar.com, then back to
foo.com, which causes the RVH to become inactive and back to active again. This
causes the RWHV to be destroyed and recreated.

This change (and the other change) initializes the mocks necessary to allow the
creation of these RWHVs.

[Charlie Reis, 2016/11/29 19:35:55]

Hmm, I don't follow.  Lots of tests do multiple navigations between sites.  That
behavior shouldn't require window resize code in all such tests.  Is there
something else about this test in particular?

If we have to keep this, it needs a comment, but I'd really like to avoid the
need for it if we can.  Navigation tests shouldn't require this.

+#endif  // OS_MACOSX
+  }
+
+  void TearDown() override {
+#if defined(OS_MACOSX)
+    ui::WindowResizeHelperMac::Get()->ShutdownForTests();
+#endif  // OS_MACOSX
+
+    BrowserWithTestWindowTest::TearDown();
   }
 
   virtual void SetSearchProvider(bool set_ntp_url, bool insecure_ntp_url) {