Win32k lockdown: move to chrome://flags, add UMA, add finch

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 026893c960dfa192355368fa38c8a0ebb9a34048..62d42148259bf3b5a686094699c8b2a8c42e4fca 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -445,6 +445,14 @@ const Experiment kExperiments[] = {
     kOsWin,
     SINGLE_VALUE_TYPE(switches::kDisableDirectWrite)
   },
+  {
+    "enable-win32k-renderer-lockdown",
+    IDS_FLAGS_ENABLE_WIN32K_RENDERER_LOCKDOWN_NAME,
+    IDS_FLAGS_ENABLE_WIN32K_RENDERER_LOCKDOWN_DESCRIPTION,
+    kOsWin,
+    ENABLE_DISABLE_VALUE_TYPE(switches::kEnableWin32kRendererLockDown,
+                              switches::kDisableWin32kRendererLockDown)
+  },
 #endif
   {
     "enable-experimental-canvas-features",