Expose FS show/hide thresholds to Command Line

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 619944058745584281693ddead3001f48580e381..85bd2f7e5ad5c1612df2acc6e87cc608454000ba 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -121,6 +121,24 @@ scoped_ptr<RenderWidgetCompositor> RenderWidgetCompositor::Create(
     settings.calculateTopControlsPosition = false;
   }
 
+  if (cmd->HasSwitch(cc::switches::kTopControlsShowThreshold)) {
+      std::string top_threshold_str =
+          cmd->GetSwitchValueASCII(cc::switches::kTopControlsShowThreshold);
+      double show_threshold;
+      if (base::StringToDouble(top_threshold_str, &show_threshold) &&
+          show_threshold >= 0.f && show_threshold <= 1.f)
+        settings.topControlsShowThreshold = show_threshold;
+  }
+
+  if (cmd->HasSwitch(cc::switches::kTopControlsHideThreshold)) {
+      std::string top_threshold_str =
+          cmd->GetSwitchValueASCII(cc::switches::kTopControlsHideThreshold);
+      double hide_threshold;
+      if (base::StringToDouble(top_threshold_str, &hide_threshold) &&
+          hide_threshold >= 0.f && hide_threshold <= 1.f)
+        settings.topControlsHideThreshold = hide_threshold;
+  }
+
   settings.partialSwapEnabled =
       cmd->HasSwitch(cc::switches::kEnablePartialSwap);
   settings.backgroundColorInsteadOfCheckerboard =