chromeos: Send 'keypress' for the content when composing a character with dead keys

This change leaves characters outside BMP unable to be typed on docs.google.com, but surely fixes the problem for most use cases.

BUG=132668
TEST=Create a document on docs.google.com and try typing a character with dead keys (e.g. type '^'+'a' with keyboard layout "English - US international")

Review URL: https://chromiumcodereview.appspot.com/10565032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@142705 0039d316-1c4b-4281-b951-d872f2087c98
void InputMethodIBus::OnHidePreeditText(IBusInputContext* context) {
  DCHECK_EQ(context_, context);
  if (composition_.text.empty() || IsTextInputTypeNone())
    return;

  composition_changed_ = true;
  composition_.Clear();

  if (pending_key_events_.empty()) {
    TextInputClient* client = GetTextInputClient();
    if (client && client->HasCompositionText())
      client->ClearCompositionText();
    composition_changed_ = false;
  }
}

void InputMethodIBus::OnHidePreeditText(IBusInputContext* context) {
  DCHECK_EQ(context_, context);
  if (composition_.text.empty() || IsTextInputTypeNone())
    return;

  composition_changed_ = true;
  composition_.Clear();

  if (pending_key_events_.empty()) {
    TextInputClient* client = GetTextInputClient();
    if (client && client->HasCompositionText())
      client->ClearCompositionText();
    composition_changed_ = false;
  }
}
