Fix a lacros crash on launch.

crashpad_handler needs to know where to put crashes. By default it uses
the default UserDataDir and does not have support for --user-data-dir.
If the default UserDataDir is not writable, then lacros fails to launch.

This CL sets --breakpad-dump-location when launching lacros, effectively
overriding the default.

Change-Id: I9e31bc14ed721a3984f42f30f94d4214d672daa3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2350124
Commit-Queue: Erik Chen <erikchen@chromium.org>
Auto-Submit: Erik Chen <erikchen@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797094}

chrome/browser/chromeos/crosapi/browser_manager.cc

@@ -185,6 +185,8 @@ bool BrowserManager::Start() {
 
   // Paths are UTF-8 safe on Chrome OS.
   std::string user_data_dir = browser_util::GetUserDataDir().AsUTF8Unsafe();
+  std::string crash_dir =
+      browser_util::GetUserDataDir().Append("crash_dumps").AsUTF8Unsafe();
 
   std::vector<std::string> argv = {chrome_path,
                                    "--ozone-platform=wayland",
@@ -192,7 +194,8 @@ bool BrowserManager::Start() {
                                    "--enable-gpu-rasterization",
                                    "--enable-oop-rasterization",
                                    "--lang=en-US",
-                                   "--enable-crashpad"};
+                                   "--enable-crashpad",
+                                   "--breakpad-dump-location=" + crash_dir};
 
   std::string additional_flags =
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
@@ -215,6 +218,8 @@ bool BrowserManager::Start() {
 
   // Set up Mojo channel.
   base::CommandLine command_line(argv);
+  LOG(WARNING) << "Launching lacros with command: "
+               << command_line.GetCommandLineString();
   mojo::PlatformChannel channel;
   channel.PrepareToPassRemoteEndpoint(&options, &command_line);