Install pywin32 into depot_tools's python.

depot_tools is currently missing pywin32 on Windows which is needed
by build/toolchain/win/tool_wrapper.py.

lib/util.js

@@ -6,12 +6,21 @@ const crypto = require('crypto')
 const autoGeneratedBraveToChromiumMapping = Object.assign({}, require('./l10nUtil').autoGeneratedBraveToChromiumMapping)
 const os = require('os')
 
+const fixPywin32 = (options = {}) => {
+  if (process.platform !== 'win32') {
+    return
+  }
+  console.log("Manually installing pywin32 python module")
+  util.run('python', ['-m', 'pip', 'install', 'pywin32'], options)
+}
+
 const runGClient = (args, options = {}) => {
   if (config.gClientVerbose) args.push('--verbose')
   options.cwd = options.cwd || config.rootDir
   options = mergeWithDefault(options)
   options.env.GCLIENT_FILE = config.gClientFile
   util.run('gclient', args, options)
+  fixPywin32(options)
 }
 
 const mergeWithDefault = (options) => {