Fix install-from-.dmg for new bundle layout

When installing from .dmg, the relauncher process is hosted by the
helper app in the the newly installed copy. Since it's invoked by the
original browser .app running from the .dmg, the path service can't be
used to obtain the path.

When the bundle layout changed (bug 958976), the path built for the
relauncher process executable by the install-from-.dmg wasn't updated.

Bug: 1004398
Change-Id: I54da7688c162349efa2db78022b3dffc378f2828
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1822158Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699376}

chrome/browser/mac/install_from_dmg.mm

@@ -357,8 +357,11 @@ bool LaunchInstalledApp(NSString* installed_path,
                         const std::string& dmg_bsd_device_name) {
   base::FilePath browser_path([installed_path fileSystemRepresentation]);
 
-  base::FilePath helper_path = browser_path.Append("Contents/Versions");
+  base::FilePath helper_path = browser_path.Append("Contents/Frameworks");
+  helper_path = helper_path.Append(chrome::kFrameworkName);
+  helper_path = helper_path.Append("Versions");
   helper_path = helper_path.Append(chrome::kChromeVersion);
+  helper_path = helper_path.Append("Helpers");
   helper_path = helper_path.Append(chrome::kHelperProcessExecutablePath);
 
   std::vector<std::string> args =