Add --disable-new-dialog-style flag; use DialogDelegate::UseNewStyle(); etc.

Add a --disable-new-dialog-style flag; matches --enable*.
Update the about:flags strings for consistency and clarity.
Use DialogDelegate::UseNewStyle() instead of checking flags.
(this is in preparation for enabling-by-default soon)

BUG=166075
TEST=The about:flags "New Dialog Style" Default/Enabled/Disabled settings and the --[en|dis]able-new-dialog-style command-line flags work as expected, default is still disabled.
[email protected]

Review URL: https://chromiumcodereview.appspot.com/14629017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@199302 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 9c13b8d..95d3f97b 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1115,11 +1115,12 @@
                               switches::kDisableViewsTextfield),
   },
   {
-    "enable-new-dialog-style",
-    IDS_FLAGS_ENABLE_NEW_DIALOG_STYLE_NAME,
-    IDS_FLAGS_ENABLE_NEW_DIALOG_STYLE_DESCRIPTION,
+    "new-dialog-style",
+    IDS_FLAGS_NEW_DIALOG_STYLE_NAME,
+    IDS_FLAGS_NEW_DIALOG_STYLE_DESCRIPTION,
     kOsWin | kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kEnableNewDialogStyle),
+    ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNewDialogStyle,
+                              switches::kDisableNewDialogStyle),
   },
   { "disable-accelerated-video-decode",
     IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_NAME,