Change style of ConstrainedWindowViews.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index bd008047d8402fc5af087e2420fe392eb8f94dbe..dc869baab6829a8bffbd0e45af993285b8c41a47 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -519,6 +519,11 @@ const char kEnableExtensionActivityUI[]     = "enable-extension-activity-ui";
 // Enables experimental timeline API.
 const char kEnableExtensionTimelineApi[]    = "enable-extension-timeline-api";
 
+// Applies a new frameless window style to any dialog based on
+// ConstrainedWindowViews.
+const char kEnableFramelessConstrainedDialogs[] =
+    "enable-frameless-constrained-dialogs";
+
 // By default, cookies are not allowed on file://. They are needed for testing,
 // for example page cycler and layout tests. See bug 1157243.
 const char kEnableFileCookies[]             = "enable-file-cookies";