Profiler: Move everything into the "Profiler" namespace

Userland/DevTools/Profiler/IndividualSampleModel.cpp

@@ -9,6 +9,8 @@
 #include <AK/StringBuilder.h>
 #include <stdio.h>
 
+namespace Profiler {
+
 IndividualSampleModel::IndividualSampleModel(Profile& profile, size_t event_index)
     : m_profile(profile)
     , m_event_index(event_index)
@@ -69,3 +71,5 @@ void IndividualSampleModel::update()
 {
     did_update(Model::InvalidateAllIndices);
 }
+
+}