Remove per-tab preference machinery.

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 3f48a85f5e250e5696e44545da60d8d5c01b15fc..8f60a3b82f324e0918b22cfb623dfdcc553d56ce 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -225,8 +225,6 @@ const char kWebKitAllowDisplayingInsecureContent[] =
     "webkit.webprefs.allow_displaying_insecure_content";
 const char kWebKitAllowRunningInsecureContent[] =
     "webkit.webprefs.allow_running_insecure_content";
-const char kWebKitXSSAuditorEnabled[] =
-    "webkit.webprefs.xss_auditor_enabled";
 
 // Settings below can be overridden for each tab individually.
 const char kDefaultCharset[] = "intl.charset_default";
@@ -248,8 +246,6 @@ const char kWebKitJavascriptCanOpenWindowsAutomatically[] =
     "webkit.webprefs.javascript_can_open_windows_automatically";
 const char kWebKitLoadsImagesAutomatically[] =
     "webkit.webprefs.loads_images_automatically";
-const char kWebKitImagesEnabled[] =
-    "webkit.webprefs.images_enabled";
 const char kWebKitPluginsEnabled[] = "webkit.webprefs.plugins_enabled";
 
 // Boolean which specifies whether the bookmark bar is visible on all tabs.