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

base/mac/mac_util.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 "base/mac/mac_util.h"
 
 #import <Cocoa/Cocoa.h>
 #import <IOKit/IOKitLib.h>
 
 #include <errno.h>
@@ skipping 384 matching lines @@
   }
   return IsHiddenLoginItem(item);
 }
 
 bool RemoveQuarantineAttribute(const FilePath& file_path) {
   const char kQuarantineAttrName[] = "com.apple.quarantine";
   int status = removexattr(file_path.value().c_str(), kQuarantineAttrName, 0);
   return status == 0 || errno == ENOATTR;
 }
 
+bool CharacterIsPrintable(unichar c) {
+  switch (c) {
+  case 0xf728:  // Delete
+    return false;
+  }
+  return true;
+}
+
+bool StringIsPrintable(NSString* s) {
+  if (s.length == 0)
+    return true;
+  for (NSUInteger i = 0; i < s.length; ++i) {
+    if (CharacterIsPrintable([s characterAtIndex:i]))
+      return true;
+  }
+  return false;
+}
+
 namespace {
 
 // Returns the running system's Darwin major version. Don't call this, it's
 // an implementation detail and its result is meant to be cached by
 // MacOSXMinorVersion.
 int DarwinMajorVersionInternal() {
   // base::OperatingSystemVersionNumbers calls Gestalt, which is a
   // higher-level operation than is needed. It might perform unnecessary
   // operations. On 10.6, it was observed to be able to spawn threads (see
   // http://crbug.com/53200). It might also read files or perform other
@@ skipping 183 matching lines @@
           StringPiece(begin + comma_loc + 1, ident.end()), &minor_tmp))
     return false;
   *type = ident.substr(0, number_loc);
   *major = major_tmp;
   *minor = minor_tmp;
   return true;
 }
 
 }  // namespace mac
 }  // namespace base