Enable widevine on all platforms

Widevine cdm pkg is downloaded by using version that is spcified in
package.json. Then it is stored to src/third_party/widevine.

widevinew version configuration is added in package.json.
adm-zip and sync-request are newly added into dependencies for
downloading widevine pkg synchronously and unzip.

lib/config.js

@@ -52,7 +52,7 @@ const Config = function () {
   this.braveReferralsApiKey = getNPMConfig(['brave_referrals_api_key']) || ''
   this.ignore_compile_failure = false
   this.enable_hangout_services_extension = true
-
+  this.widevineVersion = getNPMConfig(['widevine', 'version'])
 }
 
 Config.prototype.buildArgs = function () {
@@ -73,7 +73,7 @@ Config.prototype.buildArgs = function () {
     ffmpeg_branding: "Chrome",
     enable_nacl: false,
     // branding_path_component: "brave",
-    enable_widevine: process.platform !== 'linux',
+    enable_widevine: true,
     target_cpu: this.targetArch,
     is_official_build: this.officialBuild,
     is_debug: this.buildConfig !== 'Release',

lib/util.js

@@ -4,6 +4,8 @@ const config = require('./config')
 const fs = require('fs-extra')
 const crypto = require('crypto')
 const autoGeneratedBraveToChromiumMapping = Object.assign({}, require('./l10nUtil').autoGeneratedBraveToChromiumMapping)
+const admZip = require('adm-zip')
+const request = require('sync-request')
 
 const runGClient = (args, options = {}) => {
   if (config.gClientVerbose) args.push('--verbose')
@@ -208,6 +210,76 @@ const util = {
     fs.copySync(srcDir, dstDir)
   },
 
+  // In linux, WidevineCdm library is bundled instead of installing it by component
+  // updating during the runtime. In linux, we can't load cdm library during the runtime
+  // because processes except browser process are forked from zygote process not created from
+  // brave.exe binary. So, cdm should be loaded(not initialized) into zygote process space
+  // before zygote enters the sandbox.
+  // This method places WidevineCdm lib and header file into proper place before building.
+  prepareWidevineCdmLibIfNeeded: () => {
+    const widevineDir = path.join(config.srcDir, 'third_party', 'widevine', 'cdm', 'linux', 'x64')
+    fs.ensureDirSync(widevineDir)
+
+    const widevineConfig = {
+      widevineDir,
+      configuredVersion: config.widevineVersion,
+      versionFilePath: path.join(widevineDir, 'version'),
+      widevineCdmHeaderFilePath: path.join(widevineDir, 'widevine_cdm_version.h'),
+      widevineCdmLibFilePath: path.join(widevineDir, 'libwidevinecdm.so')
+    }
+
+    // If version file isn't existed, do fresh install.
+    if (!fs.existsSync(widevineConfig.versionFilePath)) {
+      console.log("No widevine version file.")
+      util.doPrepareWidevineCdmLib(widevineConfig)
+      return
+    }
+
+    // If installed version is different with configured version, do fresh install.
+    const installedVersion = fs.readFileSync(widevineConfig.versionFilePath, 'utf8')
+    if (installedVersion !== widevineConfig.configuredVersion) {
+      console.log("Different widevine version is installed")
+      util.doPrepareWidevineCdmLib(widevineConfig)
+      return
+    }
+
+    // Double check necessary header and lib exists.
+    if (fs.existsSync(widevineConfig.widevineCdmHeaderFilePath) &&
+        fs.existsSync(widevineConfig.widevineCdmLibFilePath))
+      return;
+
+    util.doPrepareWidevineCdmLib(widevineConfig)
+  },
+
+  doPrepareWidevineCdmLib: (widevineConfig) => {
+    console.log('Install widevinecdm library')
+
+    // Create version file.
+    fs.writeFileSync(widevineConfig.versionFilePath, widevineConfig.configuredVersion)
+
+    // Crate header file.
+    const headerFileContent =
+`#ifndef WIDEVINE_CDM_VERSION_H_
+#define WIDEVINE_CDM_VERSION_H_
+#define WIDEVINE_CDM_VERSION_STRING \"${widevineConfig.configuredVersion}\"
+#endif  // WIDEVINE_CDM_VERSION_H_`;
+    fs.writeFileSync(widevineConfig.widevineCdmHeaderFilePath, headerFileContent)
+
+    // Synchronously download widevine pkg and extracts into cdm dir.
+    const widevineZipFileName = `${widevineConfig.configuredVersion}-linux-x64.zip`
+    const widevineUrl = `https://redirector.gvt1.com/edgedl/widevine-cdm/${widevineZipFileName}`
+    const res = request('GET', widevineUrl)
+    const widevineZipFilePath = path.join(widevineConfig.widevineDir, widevineZipFileName)
+    fs.writeFileSync(widevineZipFilePath, res.body)
+    const zip = new admZip(widevineZipFilePath);
+    zip.extractAllTo(widevineConfig.widevineDir, true)
+    // During the create_dist, /usr/lib/rpm/elfdeps requires that binaries have an exectuable bit set.
+    fs.chmodSync(widevineConfig.widevineCdmLibFilePath, 0o755)
+
+    // Delete zip file.
+    fs.removeSync(widevineZipFilePath)
+  },
+
   signApp: (options = config.defaultOptions) => {
     console.log('signing ...')
 
@@ -218,6 +290,7 @@ const util = {
     console.log('building ' + config.buildTarget + '...')
 
     if (process.platform === 'win32') util.updateOmahaMidlFiles()
+    if (process.platform === 'linux') util.prepareWidevineCdmLibIfNeeded()
 
     let num_compile_failure = 1
     if (config.ignore_compile_failure)

package.json

@@ -47,6 +47,9 @@
           "url": "https://github.com/brave/brave-core.git"
         }
       }
+    },
+    "widevine": {
+      "version": "4.10.1196.0"
     }
   },
   "repository": {
@@ -252,8 +255,10 @@
   },
   "homepage": "https://github.com/brave/brave-browser#readme",
   "dependencies": {
+    "adm-zip": "^0.4.13",
     "commander": "^2.9.0",
-    "fs-extra": "^1.0.0"
+    "fs-extra": "^1.0.0",
+    "sync-request": "^6.0.0"
   },
   "devDependencies": {
     "ip": "^1.1.5"