Attach (recommended) or Link to PDF file here:
[298865.pdf](https://github.com/mozilla/pdf.js/files/2753236/298865.pdf)


Configuration:
- Web browser and its version:chrome 71.0.3578.98
- Operating system and its version:mac os 10.12.6
- PDF.js version:I use online demo in github
- Is a browser extension:no

Steps to reproduce the problem:
1. search "中华" or "电力" or so on,the highlight position is not right

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/10000986/51087378-7eff5100-178d-11e9-991a-005d77b82f31.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/10000986/51087374-6ee77180-178d-11e9-9707-281924f95fd0.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):
https://mozilla.github.io/pdf.js/web/viewer.html
.getAnnotations({ intent: "any" })
        .then(function (data) {
          expect(data.length).toEqual(4);
        });
      const displayPromise = page
        .getAnnotations({ intent: "display" })
        .then(function (data) {
          expect(data.length).toEqual(4);
        });
      const printPromise = page
        .getAnnotations({ intent: "print" })
        .then(function (data) {
          expect(data.length).toEqual(4);
        });
      await Promise.all([
        defaultPromise,
        anyPromise,
        displayPromise,
        printPromise,
      ]);
    });
    it("gets annotations containing relative URLs (bug 766086)", async function () {
      const filename = "bug766086.pdf";
      const defaultLoadingTask = getDocument(buildGetDocumentParams(filename));
      const defaultPromise = defaultLoadingTask.promise.then(function (pdfDoc) {
        return pdfDoc.getPage(1).then(function (pdfPage) {
          return pdfPage.getAnnotations();
        });
      });
      const docBaseUrlLoadingTask = getDocument(