Change the floc blocklist install dir to a new subdirectory

Why: There's going to be a new component to be synced for the FLoC
project. So we want that and the existing blocklist to be contained in
different subdirectories under the same top directory.

Bug: 1062736
Change-Id: I730d01a086828feab19acf42361cea8efe9be3ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416729
Commit-Queue: Yao Xiao <yaoxia@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Reviewed-by: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810723}

chrome/browser/component_updater/floc_blocklist_component_installer.cc

@@ -78,7 +78,8 @@ bool FlocBlocklistComponentInstallerPolicy::VerifyInstallation(
 
 base::FilePath FlocBlocklistComponentInstallerPolicy::GetRelativeInstallDir()
     const {
-  return base::FilePath(federated_learning::kTopLevelDirectoryName);
+  return base::FilePath(federated_learning::kTopLevelDirectoryName)
+      .Append(federated_learning::kBlocklistBaseDirectoryName);
 }
 
 void FlocBlocklistComponentInstallerPolicy::GetHash(

components/federated_learning/floc_constants.cc

@@ -13,6 +13,9 @@ const int kCurrentBlocklistFormatVersion = 1;
 const base::FilePath::CharType kTopLevelDirectoryName[] =
     FILE_PATH_LITERAL("Floc");
 
+const base::FilePath::CharType kBlocklistBaseDirectoryName[] =
+    FILE_PATH_LITERAL("Blocklist");
+
 const base::FilePath::CharType kBlocklistFileName[] =
     FILE_PATH_LITERAL("Blocklist");
 

components/federated_learning/floc_constants.h

@@ -18,6 +18,14 @@ extern const int kCurrentBlocklistFormatVersion;
 extern const base::FilePath::CharType kTopLevelDirectoryName[];
 
 // Paths under |kTopLevelDirectoryName|
+// ------------------------------------
+
+// The name of the subdirectory under the top-level directory that stores
+// blocklist downloaded through the component updater.
+extern const base::FilePath::CharType kBlocklistBaseDirectoryName[];
+
+// Paths under kBlocklistBaseDirectoryName
+// ---------------------------------------
 
 // The name of the file that stores the blocklist.
 extern const base::FilePath::CharType kBlocklistFileName[];