Fix duplicate extensions in the profile loading error message

Source/devtools/front_end/profiler/ProfilesPanel.js

Index: Source/devtools/front_end/profiler/ProfilesPanel.js
diff --git a/Source/devtools/front_end/profiler/ProfilesPanel.js b/Source/devtools/front_end/profiler/ProfilesPanel.js
index 8012b02877985906c67ddf07a2221ffdb859488b..482e88b2159747ec139980552a2fb9705dfa3d7c 100644
--- a/Source/devtools/front_end/profiler/ProfilesPanel.js
+++ b/Source/devtools/front_end/profiler/ProfilesPanel.js
@@ -583,7 +583,7 @@ WebInspector.ProfilesPanel.prototype = {
             var types = WebInspector.ProfileTypeRegistry.instance.profileTypes();
             for (var i = 0; i < types.length; i++) {
                 var extension = types[i].fileExtension();
-                if (!extension)
+                if (!extension || extensions.indexOf(extension) !== -1)
                     continue;
                 extensions.push(extension);
             }