Compile-time and run-time flags for top chrome material design.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 2bfba152e8b0e3580d17831501f8dc5ce27070c1..431f30bbc5439751c55723f41f7d102209b239a6 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -889,6 +889,17 @@ const Experiment kExperiments[] = {
     kOsDesktop,
     SINGLE_VALUE_TYPE(switches::kEnableScrollPrediction)
   },
+#if defined(ENABLE_TOPCHROME_MD)
+  {
+    "top-chrome-md",
+    IDS_FLAGS_TOP_CHROME_MD,
+    IDS_FLAGS_TOP_CHROME_MD_DESCRIPTION,
+    kOsWin | kOsCrOS,
+    ENABLE_DISABLE_VALUE_TYPE(
+    switches::kTopChromeMDEnabled,
+    switches::kTopChromeMDDisabled)
+  },
+#endif
   {
     "touch-events",
     IDS_TOUCH_EVENTS_NAME,