Correct new mini_chromium locations for external.

Followup to crrev.com/c/3062424 to fix Keystone build.

Change-Id: I637897d961b65923534748591063ee1456fd193e
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3231491
Commit-Queue: David Fang <fangism@google.com>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
GitOrigin-RevId: 31d9206f059fe9c5299be52870d9fad595fb543d
diff --git a/build/crashpad_buildconfig.gni b/build/crashpad_buildconfig.gni
index a9a8a10..e6e51e8 100644
--- a/build/crashpad_buildconfig.gni
+++ b/build/crashpad_buildconfig.gni
@@ -36,10 +36,7 @@
 
 # This is the parent directory that contains the mini_chromium source dir.
 # This variable is not used when crashpad_is_in_chromium.
-if (crashpad_is_external || crashpad_is_in_dart) {
-  # External and Dart SDK builds assume crashpad and mini_chromium are peers.
-  mini_chromium_source_parent = "../mini_chromium"
-} else if (crashpad_is_in_fuchsia) {
+if (crashpad_is_in_fuchsia) {
   mini_chromium_source_parent = "//third_party/crashpad/third_party/mini_chromium"
 } else {
   mini_chromium_source_parent = "../third_party/mini_chromium"
@@ -50,7 +47,7 @@
 
 # This references the mini_chromium location for importing GN files.
 if (crashpad_is_external || crashpad_is_in_dart) {
-  mini_chromium_import_root = "../../$_mini_chromium_source_root"
+  mini_chromium_import_root = "../../../$_mini_chromium_source_root"
 } else if (crashpad_is_in_fuchsia) {
   mini_chromium_import_root = "//third_party/mini_chromium"
 } else {
@@ -70,6 +67,7 @@
   crashpad_is_clang = is_clang
 } else {
   import("$mini_chromium_import_root/build/compiler.gni")
+  import("$mini_chromium_import_root/build/platform.gni")
 
   crashpad_is_mac = mini_chromium_is_mac
   crashpad_is_ios = mini_chromium_is_ios