Here, i have attached the PDF, that PDF document contains "Nudi" as an embedded font. When i searching the particular word (that in Nudi font), the search result selecting the word that context next to the exact word.

Link to PDF file (or attach file here):
[sample_pdf.zip](https://github.com/mozilla/pdf.js/files/229582/sample_pdf.zip)

Configuration:
- Web browser and its version: Mozilla 45.0.2
- Operating system and its version: Windows 7
- PDF.js version: 1.4.20-disc

What is the expected behavior? (add screenshot)
![find_01](https://cloud.githubusercontent.com/assets/17423938/14704922/c2e67f2c-07d4-11e6-9320-9aed2578d377.png)

if (query.length === 0) {
      
      return;
    }
    if (!caseSensitive) {
      pageContent = pageContent.toLowerCase();
      query = query.toLowerCase();
    }
    if (phraseSearch) {
      this._calculatePhraseMatch(query, pageIndex, pageContent, entireWord);
    } else {
      this._calculateWordMatch(query, pageIndex, pageContent, entireWord);
    }
    
    
    if (this._state.highlightAll) {
      this._updatePage(pageIndex);
    }
    if (this._resumePageIdx === pageIndex) {
      this._resumePageIdx = null;
      this._nextPageMatch();
    }
    
    const pageMatchesCount = this._pageMatches[pageIndex].length;
    if (pageMatchesCount > 0) {
      this._matchesCountTotal += pageMatchesCount;
      this._updateUIResultsCount();
    }
  }
  _extractText() {