Disable magnification palette tool unless experimental palette features are enabled.

ash/common/system/chromeos/palette/palette_utils.cc

Index: ash/common/system/chromeos/palette/palette_utils.cc
diff --git a/ash/common/system/chromeos/palette/palette_utils.cc b/ash/common/system/chromeos/palette/palette_utils.cc
index 704dbce8e1d4d56b870500f68df5423e4e518b8d..6a76068e90e36ebb1cf76aeeedba22767956d69a 100644
--- a/ash/common/system/chromeos/palette/palette_utils.cc
+++ b/ash/common/system/chromeos/palette/palette_utils.cc
@@ -14,4 +14,9 @@ bool IsPaletteFeatureEnabled() {
       switches::kAshEnablePalette);
 }
 
+bool ArePaletteExperimentalFeaturesEnabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kAshEnableExperimentalPaletteFeatures);
+}
+
 }  // namespace ash