Move app_shell specific impl from athena_lib to athena_shell_lib

athena/content/app_activity_unittest.cc

Index: athena/content/app_activity_unittest.cc
diff --git a/athena/content/app_activity_unittest.cc b/athena/content/app_activity_unittest.cc
index d0544f05f13aa18b8019106c31ba8a50bb88c9a3..c62b374c37c5288e8c4026b8334a88b41db13737 100644
--- a/athena/content/app_activity_unittest.cc
+++ b/athena/content/app_activity_unittest.cc
@@ -13,7 +13,6 @@
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
-
 namespace content {
 class BrowserContext;
 }
@@ -31,7 +30,7 @@ const char kDummyApp2[] = "bbbbbbb";
 class TestAppActivity : public AppActivity {
  public:
   explicit TestAppActivity(const std::string& app_id) :
-      AppActivity(NULL),
+      AppActivity(),
       app_id_(app_id),
       view_(new views::View()),
       current_state_(ACTIVITY_VISIBLE) {
@@ -67,6 +66,11 @@ class TestAppActivity : public AppActivity {
     return view_->GetWidget()->GetNativeWindow();
   }
 
+  // AppActivity:
+  virtual content::WebContents* GetWebContents() OVERRIDE {
+    return NULL;
+  }
+
   // ActivityViewModel:
   virtual void Init() OVERRIDE {}
   virtual SkColor GetRepresentativeColor() const OVERRIDE { return 0; }