MacKeyboard: Don't generate keypress for non-printable char

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 2279 matching lines @@
     if (!textInserted && textToBeInserted_.length() == 1) {
       // If a single character was inserted, then we just send it as a keypress
       // event.
       event.type = blink::WebInputEvent::Char;
       event.text[0] = textToBeInserted_[0];
       event.text[1] = 0;
       event.skip_in_browser = true;
       widgetHost->ForwardKeyboardEvent(event);
     } else if ((!textInserted || delayEventUntilAfterImeCompostion) &&
                [[theEvent characters] length] > 0 &&
+               base::mac::StringIsPrintable([theEvent characters]) &&
                (([theEvent modifierFlags] & kCtrlCmdKeyMask) ||
                 (hasEditCommands_ && editCommands_.empty()))) {
       // We don't get insertText: calls if ctrl or cmd is down, or the key event
       // generates an insert command. So synthesize a keypress event for these
       // cases, unless the key event generated any other command.
       event.type = blink::WebInputEvent::Char;
       event.skip_in_browser = true;
       widgetHost->ForwardKeyboardEvent(event);
     }
   }
@@ skipping 1131 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end