Record metrics for permission prompt acceptance vs. user gesture.

chrome/browser/permissions/permission_request.cc

Index: chrome/browser/permissions/permission_request.cc
diff --git a/chrome/browser/permissions/permission_request.cc b/chrome/browser/permissions/permission_request.cc
index 311444af08a870914382417fa3f881319eb3b544..ba24d376abc37915d5138021fd5e5998bc64b3f0 100644
--- a/chrome/browser/permissions/permission_request.cc
+++ b/chrome/browser/permissions/permission_request.cc
@@ -13,3 +13,7 @@ gfx::VectorIconId PermissionRequest::GetVectorIconId() const {
 PermissionRequestType PermissionRequest::GetPermissionRequestType() const {
   return PermissionRequestType::UNKNOWN;
 }
+
+PermissionRequestGestureType PermissionRequest::GetGestureType() const {
+  return PermissionRequestGestureType::UNKNOWN;
+}