Added field trial for enabling AppContainer and a chrome://flags entry.

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 74ac83c4d1590f4d2d7026dc7ccbe1deae0796dd..baa89adcbd0b554754d16a43966d9fb692fb2592 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -592,8 +592,9 @@ const char kNoReferrers[]                   = "no-referrers";
 // Disables the sandbox for all process types that are normally sandboxed.
 const char kNoSandbox[]                     = "no-sandbox";
 
-// Enables appcontainer/lowbox for renderer on Win8+ platforms.
+// Enable or disable appcontainer/lowbox for renderer on Win8+ platforms.
 const char kEnableAppContainer[]           = "enable-appcontainer";
+const char kDisableAppContainer[]          = "disable-appcontainer";
 
 // Number of worker threads used to rasterize content.
 const char kNumRasterThreads[]              = "num-raster-threads";