Fixed and reenabled the flaky test "WebViewAPITest.TestAutosizeAfterNavigation".

content/public/browser/browser_plugin_guest_delegate.h

Index: content/public/browser/browser_plugin_guest_delegate.h
diff --git a/content/public/browser/browser_plugin_guest_delegate.h b/content/public/browser/browser_plugin_guest_delegate.h
index 8c8a10c464c14431aef116167e833394c91d23c4..5e5d1fea4e51ed038d31fa84bc29b27f7524cdf9 100644
--- a/content/public/browser/browser_plugin_guest_delegate.h
+++ b/content/public/browser/browser_plugin_guest_delegate.h
@@ -58,10 +58,9 @@ class CONTENT_EXPORT BrowserPluginGuestDelegate {
   virtual WebContents* GetOwnerWebContents() const;
 
   // Notifies that the content size of the guest has changed.
-  // Note: In autosize mode, it si possible that the guest size may not match
+  // Note: In autosize mode, it is possible that the guest size may not match
   // the element size.
-  virtual void GuestSizeChanged(const gfx::Size& old_size,
-                                const gfx::Size& new_size) {}
+  virtual void GuestSizeChanged(const gfx::Size& new_size) {}
 
   // Asks the delegate if the given guest can lock the pointer.
   // Invoking the |callback| synchronously is OK.