[WebView] Remove more redundant classes

android_webview/browser/aw_web_preferences_populater.h

Index: android_webview/browser/aw_web_preferences_populater.h
diff --git a/android_webview/browser/aw_web_preferences_populater.h b/android_webview/browser/aw_web_preferences_populater.h
index 6fbd76ba9e0dc90bee97265318b1350173613de0..8d48cd4fd8a4ecf69005efc52e9e0d0b9344d605 100644
--- a/android_webview/browser/aw_web_preferences_populater.h
+++ b/android_webview/browser/aw_web_preferences_populater.h
@@ -15,10 +15,11 @@ namespace android_webview {
 // Empty base class so this can be destroyed by AwContentBrowserClient.
 class AwWebPreferencesPopulater {
  public:
-  virtual ~AwWebPreferencesPopulater();
+  AwWebPreferencesPopulater() = default;
+  ~AwWebPreferencesPopulater() = default;
 
-  virtual void PopulateFor(content::WebContents* web_contents,
-                           content::WebPreferences* web_prefs) = 0;
+  void PopulateFor(content::WebContents* web_contents,
+                   content::WebPreferences* web_prefs);
 };
 
 }  // namespace android_webview