#### NOTE: I'm opening a separate issue to #1005 because this is a separate regression - in ^4.0.0, this still worked.

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### Issue Details

* **Electron Version:**
  * 5.0.2
* **Operating System:**
  * Windows 10 x64 latest
* **Last Known Working Electron version:**
  * 4.2.2

### Expected Behavior
The spellchecker is correctly called with contractions (and their parts)

### Actual Behavior
The spellchecker is now only called with the parts of the contractions.

### To Reproduce
Just use the spellcheck API anywhere.

### Additional Information
In ^4.0.0, the spellcheck API would call the spellchecker with first the contraction and then its parts (i.e. for `couldn't` it would be called with `couldn't`, `couldn`, `t` in order). The new ^5.0.0 API calls the spellchecker with an array of just the parts (i.e. for `couldn't` it would be called with `['couldn', 't']`. Therefore, it is now completely impossible to correctly handle contractions.

Thank you for looking into this. <3
atom/renderer/api/atom_api_spell_check_client.cc
context_.Reset();
}
void SpellCheckClient::RequestCheckingOfText(
    const blink::WebString& textToCheck,
    std::unique_ptr<blink::WebTextCheckingCompletion> completionCallback) {
  base::string16 text(textToCheck.Utf16());
  
  if (text.empty() || !HasWordCharacters(text, 0)) {
    completionCallback->DidCancelCheckingText();
    return;
  }
  
  if (pending_request_param_) {
    pending_request_param_->completion()->DidCancelCheckingText();
  }
  pending_request_param_.reset(
      new SpellcheckRequest(text, std::move(completionCallback)));
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::BindOnce(&SpellCheckClient::SpellCheckText, AsWeakPtr()));
}
bool SpellCheckClient::IsSpellCheckingEnabled() const {
  return true;
}
void SpellCheckClient::ShowSpellingUI(bool show) {}
bool SpellCheckClient::IsShowingSpellingUI() {
  return false;
}
void SpellCheckClient::UpdateSpellingUIWithMisspelledWord(