Added flags for PrintBrowser mode

printing/features/features.gni

Index: printing/features/features.gni
diff --git a/printing/features/features.gni b/printing/features/features.gni
index 651b7a7a221169526a914fd03227e8cadc8e0559..2d653110fc00639a358c023e239cf48ebd5cc0f0 100644
--- a/printing/features/features.gni
+++ b/printing/features/features.gni
@@ -16,6 +16,11 @@ declare_args() {
   use_cups = (is_desktop_linux || is_mac) && !is_chromecast
 }
 

[Vitaly Buka (NO REVIEWS), 2016/12/15 00:19:49]

What is the purpose of ENABLE_PRINT_BROWSER if its value is the same as
ENABLE_PRINT_PREVIEW?

Maybe just use ENABLE_PRINT_PREVIEW?

+declare_args() {
+  # Enable Print Browser mode. Defaults to enable_print_preview.
+  enable_print_browser = enable_print_preview
+}
+
 if ((enable_basic_printing && is_win) || enable_print_preview) {
   # Windows basic printing or print preview requires pdf enabled.
   assert(enable_pdf,