fix: Fix Chromedriver download for version 115+ (shaka-project#28)

Chrome has a new distribution system since version 115.

chrome.js

@@ -11,6 +11,9 @@ const os = require('os');
 const path = require('path');
 
 const CDN_URL = 'https://chromedriver.storage.googleapis.com';
+const VERSION_DATA_URL = 'https://googlechromelabs.github.io/chrome-for-testing/latest-versions-per-milestone-with-downloads.json';
+// Chrome distribution changed in version 115.
+const NEW_CHROME_DISTRIBUTION_VERSION = 115;
 
 /**
  * An installer for chromedriver for desktop Chrome.
@@ -64,10 +67,26 @@ class ChromeWebDriverInstaller extends WebDriverInstallerBase {
    */
   async getBestDriverVersion(browserVersion) {
     const idealMajorVersion = parseInt(browserVersion.split('.')[0], 10);
-    return await InstallerUtils.fetchVersionUrlWithAutomaticDowngrade(
-        idealMajorVersion,
-        /* minMajorVersion */ idealMajorVersion - 2,
-        (majorVersion) => `${CDN_URL}/LATEST_RELEASE_${majorVersion}`);
+
+    if (idealMajorVersion < NEW_CHROME_DISTRIBUTION_VERSION) {
+      return await InstallerUtils.fetchVersionUrl(
+          `${CDN_URL}/LATEST_RELEASE_${idealMajorVersion}`);
+    } else {
+      const data = await this.getVersionData_();
+
+      // Fall back on the major version if necessary.
+      // We haven't seen this become necessary yet since the new distribution
+      // mechanism debuted, but better safe than sorry.
+      let majorVersion = idealMajorVersion;
+      while (majorVersion >= NEW_CHROME_DISTRIBUTION_VERSION) {
+        if (majorVersion in data['milestones']) {
+          return data['milestones'][majorVersion]['version'];
+        }
+        majorVersion -= 1;
+      }
+
+      throw new Error(`Unable to locate chromedriver ${idealMajorVersion}!`);
+    }
   }
 
   /**
@@ -76,12 +95,31 @@ class ChromeWebDriverInstaller extends WebDriverInstallerBase {
    * @return {!Promise}
    */
   async install(driverVersion, outputDirectory) {
+    const majorVersion = parseInt(driverVersion.split('.')[0], 10);
+
+    if (majorVersion < NEW_CHROME_DISTRIBUTION_VERSION) {
+      await this.installOld_(driverVersion, outputDirectory);
+    } else {
+      await this.installNew_(majorVersion, driverVersion, outputDirectory);
+    }
+  }
+
+  /**
+   * @param {string} driverVersion
+   * @param {string} outputDirectory
+   * @return {!Promise}
+   */
+  async installOld_(driverVersion, outputDirectory) {
     let platform;
 
     if (os.platform() == 'linux') {
       platform = 'linux64';
     } else if (os.platform() == 'darwin') {
-      platform = 'mac64';
+      if (process.arch == 'arm64') {
+        platform = 'mac_arm64';
+      } else {
+        platform = 'mac64';
+      }
     } else if (os.platform() == 'win32') {
       platform = 'win32';
     } else {
@@ -105,6 +143,73 @@ class ChromeWebDriverInstaller extends WebDriverInstallerBase {
         archiveUrl, binaryName, outputName,
         outputDirectory, /* isZip= */ true);
   }
+
+  /**
+   * @param {number} majorVersion
+   * @param {string} driverVersion
+   * @param {string} outputDirectory
+   * @return {!Promise}
+   */
+  async installNew_(majorVersion, driverVersion, outputDirectory) {
+    let platform;
+
+    if (os.platform() == 'linux') {
+      platform = 'linux64';
+    } else if (os.platform() == 'darwin') {
+      if (process.arch == 'arm64') {
+        platform = 'mac-arm64';
+      } else {
+        platform = 'mac-x64';
+      }
+    } else if (os.platform() == 'win32') {
+      platform = 'win64';
+    } else {
+      throw new Error(`Unrecognized platform: ${os.platform()}`);
+    }
+
+    let binaryName = `chromedriver-${platform}/chromedriver`;
+    if (os.platform() == 'win32') {
+      binaryName += '.exe';
+    }
+
+    let outputName = this.getDriverName();
+    if (os.platform() == 'win32') {
+      outputName += '.exe';
+    }
+
+    const data = await this.getVersionData_();
+    const downloads = data['milestones'][majorVersion]['downloads']['chromedriver'];
+
+    let archiveUrl;
+    for (const download of downloads) {
+      if (download['platform'] == platform) {
+        archiveUrl = download['url'];
+        break;
+      }
+    }
+
+    if (!archiveUrl) {
+      throw new Error(
+          `Unable to locate chromedriver ${majorVersion} for ${platform}!`);
+    }
+
+    return await InstallerUtils.installBinary(
+        archiveUrl, binaryName, outputName,
+        outputDirectory, /* isZip= */ true);
+  }
+
+  /**
+   * @return {!Object}
+   * @private
+   */
+  async getVersionData_() {
+    if (!this.versionDataCache_) {
+      const response = await InstallerUtils.fetchUrl(VERSION_DATA_URL);
+      this.versionDataCache_ = await response.json();
+    }
+
+    return this.versionDataCache_;
+  }
 }
 
 module.exports = {ChromeWebDriverInstaller};