Implement WebContentsView::GetDropData for Mac; disable on Aura

chrome/common/extensions/extension_switch_utils.cc

Index: chrome/common/extensions/extension_switch_utils.cc
diff --git a/chrome/common/extensions/extension_switch_utils.cc b/chrome/common/extensions/extension_switch_utils.cc
index 77bac1c074fd7e48d23406d0a6bbe5d9c656e572..7f4dcf6964e787935f0a62a5f19c6bb9e5768c5b 100644
--- a/chrome/common/extensions/extension_switch_utils.cc
+++ b/chrome/common/extensions/extension_switch_utils.cc
@@ -12,8 +12,14 @@ namespace extensions {
 namespace switch_utils {
 
 bool IsOffStoreInstallEnabled() {
+  // Disabling off-store installation is not yet implemented for Aura. Not sure
+  // what the Aura equivalent for this UI is.
+#if defined(USE_AURA)
+  return true;
+#else
   return !CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kDisableOffStoreExtensionInstall);
+#endif
 }
 
 }  // switch_utils