Add a policy to re-enable deprecated web platform features.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 6d50a5fea9bb9f0aa198f0fb8ecc0acd788f8657..60d25dcf3f553bd049289dbe7786379e133bfbf4 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -259,6 +259,7 @@ const char kWebKitAllowDisplayingInsecureContent[] =
     "webkit.webprefs.allow_displaying_insecure_content";
 const char kWebKitAllowRunningInsecureContent[] =
     "webkit.webprefs.allow_running_insecure_content";
+
 #if defined(OS_ANDROID)
 const char kWebKitFontScaleFactor[] = "webkit.webprefs.font_scale_factor";
 const char kWebKitForceEnableZoom[] = "webkit.webprefs.force_enable_zoom";
@@ -1135,6 +1136,9 @@ const char kMediaDeviceIdSalt[] = "media.device_id_salt";
 // Preference to disable 3D APIs (WebGL, Pepper 3D).
 const char kDisable3DAPIs[] = "disable_3d_apis";
 
+const char kEnableDeprecatedWebPlatformFeatures[] =
+    "enable_deprecated_web_platform_features";
+
 // Whether to enable hyperlink auditing ("<a ping>").
 const char kEnableHyperlinkAuditing[] = "enable_a_ping";