Add a basic test for main frame swap.

Source/web/tests/WebFrameTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 6507 matching lines @@
         m_webViewHelper.initializeAndLoad(m_baseURL + "frame-a-b-c.html");
     }
 
     void reset() { m_webViewHelper.reset(); }
     WebFrame* mainFrame() const { return m_webViewHelper.webView()->mainFrame(); }
 
 private:
     FrameTestHelpers::WebViewHelper m_webViewHelper;
 };
 
-// FIXME: We should have tests for main frame swaps, but it interacts poorly
-// with the geolocation inspector agent, since the lifetime of the inspector
-// agent is tied to the Page, but the inspector agent is created by the
-// instantiation of the main frame.
+TEST_F(WebFrameSwapTest, SwapMainFrame)
+{
+    WebFrame* remoteFrame = WebRemoteFrame::create(0);
+    mainFrame()->swap(remoteFrame);
+
+    FrameTestHelpers::TestWebFrameClient client;
+    WebFrame* localFrame = WebLocalFrame::create(&client);
+    remoteFrame->swap(localFrame);
+
+    // Finally, make sure an embedder triggered load in the local frame swapped
+    // back in works.
+    FrameTestHelpers::loadFrame(localFrame, m_baseURL + "subframe-hello.html");
+    std::string content = localFrame->contentAsText(1024).utf8();
+    EXPECT_EQ("hello", content);
+
+    // Manually reset to break WebViewHelper's dependency on the stack allocated
+    // TestWebFrameClient.
+    reset();
+    remoteFrame->close();
+}
 
 void swapAndVerifyFirstChildConsistency(const char* const message, WebFrame* parent, WebFrame* newChild)
 {
     SCOPED_TRACE(message);
     parent->firstChild()->swap(newChild);
 
     EXPECT_EQ(newChild, parent->firstChild());
     EXPECT_EQ(newChild->parent(), parent);
     EXPECT_EQ(newChild, parent->lastChild()->previousSibling()->previousSibling());
     EXPECT_EQ(newChild->nextSibling(), parent->lastChild()->previousSibling());
@@ skipping 240 matching lines @@
     EXPECT_EQ(1u, frameClient.navigationalDataReceivedCount());
 
     // Neither should a page reload.
     localFrame->reload();
     EXPECT_EQ(4u, frameClient.provisionalLoadCount());
     EXPECT_FALSE(frameClient.wasLastProvisionalLoadATransition());
     EXPECT_EQ(1u, frameClient.navigationalDataReceivedCount());
 }
 
 } // namespace