Bypass key event suppression for PrintScreen

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 5e57094a1ac9f7a891f91b77b7cf643fce0768ed..474b8bf251ab597edea4bd15944e4b8985e72cc6 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -83,6 +83,7 @@
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/events/blink/web_input_event_traits.h"
 #include "ui/events/event.h"
+#include "ui/events/keycodes/dom/dom_code.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/color_space.h"
 #include "ui/gfx/geometry/size_conversions.h"
@@ -1208,7 +1209,14 @@ void RenderWidgetHostImpl::ForwardKeyboardEvent(
   if (!WebInputEvent::isKeyboardEventType(key_event.type()))
     return;
 
-  if (suppress_events_until_keydown_) {
+  // For PrintScreen, a lone KeyUp event arrives. Bypass the suppression in this

[sadrul, 2017/01/23 18:18:35]

Is this the case on all platforms?

[foolip, 2017/01/24 04:38:12]

I tested Windows and Linux then, on Mac there isn't a PrintScreen key and I
didn't test using an external keyboard.

+  // case, as a |SuppressEventsUntilKeyDown()| call otherwise causes the keyup
+  // events to go missing.
+  // TODO(foolip): Remove this special case by instead removing the
+  // |SuppressEventsUntilKeyDown()| call. https://crbug.com/668969
+  bool is_print_screen =
+      static_cast<ui::DomCode>(key_event.domCode) == ui::DomCode::PRINT_SCREEN;
+  if (suppress_events_until_keydown_ && !is_print_screen) {
     // If the preceding RawKeyDown event was handled by the browser, then we
     // need to suppress all events generated by it until the next RawKeyDown or
     // KeyDown event.