[Athena] Hack to display favicons for web activities in overview mode

athena/test/sample_activity.cc

Index: athena/test/sample_activity.cc
diff --git a/athena/test/sample_activity.cc b/athena/test/sample_activity.cc
index 10bf2630dade1a4995c401f4c6bba2a3e51caab2..a77e194b9bb12d470f3046fd1e1a6dd9867d4ed4 100644
--- a/athena/test/sample_activity.cc
+++ b/athena/test/sample_activity.cc
@@ -60,6 +60,10 @@ base::string16 SampleActivity::GetTitle() const {
   return title_;
 }
 
+gfx::ImageSkia SampleActivity::GetIcon() const {
+  return gfx::ImageSkia();
+}
+
 bool SampleActivity::UsesFrame() const {
   return true;
 }