Revert of Remove dependency of c/b/loader on c/b/host_zoom_map_impl.h

content/browser/host_zoom_map_impl.h

Index: content/browser/host_zoom_map_impl.h
diff --git a/content/browser/host_zoom_map_impl.h b/content/browser/host_zoom_map_impl.h
index ad4c07e16c4247885814cbccfe96454f79fcfd05..ea323f3e15cfd57a6a2df1bbe34a4dab0f117a1d 100644
--- a/content/browser/host_zoom_map_impl.h
+++ b/content/browser/host_zoom_map_impl.h
@@ -149,6 +149,8 @@
   // Page scale factor data for each renderer.
   ViewPageScaleFactorsAreOne view_page_scale_factors_are_one_;
 
+  // Don't expect more than a couple of tabs that are using a temporary zoom
+  // level, so vector is fine for now.
   TemporaryZoomLevels temporary_zoom_levels_;
 
   // Used around accesses to |host_zoom_levels_|, |default_zoom_level_|,