Replace ~/Downloads to ~/MyFiles/Downloads

This is part of the "removal of Downloads bind mount" efforts,
the ~/Downloads won't exist any more after the migration, so
before that, we need to replace all existing references of
~/Downloads in Tast test to ~/MyFiles/Downloads.

Bug: b:253122024
Test: CQ
Change-Id: I9398852a63214481169a5ad80f405cf9a566d3c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5433633
Reviewed-by: Rakina Zata Amni <[email protected]>
Reviewed-by: François Degros <[email protected]>
Commit-Queue: Wenbo Jie <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1284279}
diff --git a/content/shell/browser/shell_download_manager_delegate.cc b/content/shell/browser/shell_download_manager_delegate.cc
index 0f3f9597..f6baa53 100644
--- a/content/shell/browser/shell_download_manager_delegate.cc
+++ b/content/shell/browser/shell_download_manager_delegate.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <string>
 
+#include "base/files/file_path.h"
 #include "build/build_config.h"
 #include "components/download/public/common/download_target_info.h"
 
@@ -69,8 +70,12 @@
   // This assignment needs to be here because even at the call to
   // SetDownloadManager, the system is not fully initialized.
   if (default_download_path_.empty()) {
-    default_download_path_ = download_manager_->GetBrowserContext()->GetPath().
-        Append(FILE_PATH_LITERAL("Downloads"));
+    default_download_path_ = download_manager_->GetBrowserContext()
+                                 ->GetPath()
+#if BUILDFLAG(IS_CHROMEOS)
+                                 .Append(FILE_PATH_LITERAL("MyFiles"))
+#endif
+                                 .Append(FILE_PATH_LITERAL("Downloads"));
   }
 
   if (!download->GetForcedFilePath().empty()) {