Print Preview: Add "print preview" back to about:flags; enable it by default just once.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
===================================================================
--- chrome/common/chrome_switches.cc	(revision 97007)
+++ chrome/common/chrome_switches.cc	(working copy)
@@ -1169,21 +1169,18 @@
 const char kTouchDevices[]                  = "touch-devices";
 #endif
 
-#if defined(GOOGLE_CHROME_BUILD) && !defined(OS_CHROMEOS) && !defined(OS_MACOSX)
 // Disable print preview (Not exposed via about:flags. Only used for testing.)
 const char kDisablePrintPreview[]           = "disable-print-preview";
 
-bool IsPrintPreviewEnabled() {
-  return !CommandLine::ForCurrentProcess()->HasSwitch(kDisablePrintPreview);
-}
-#else
 // Enable print preview (no PDF viewer, thus not supported with Chromium).
+// kDisablePrintPreview overrides this.
 const char kEnablePrintPreview[]            = "enable-print-preview";
 
 bool IsPrintPreviewEnabled() {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(kDisablePrintPreview))
+    return false;
   return CommandLine::ForCurrentProcess()->HasSwitch(kEnablePrintPreview);
 }
-#endif
 
 bool IsInBrowserThumbnailingEnabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(