Revert of Remove ExtensionService Garbage-Collecting methods. (https://codereview.chromium.org/204983020/)

Reason for revert:
Launch the browser and just wait a bit, eventually it crashes with:

[6912:6955:0328/131903:FATAL:weak_ptr.cc(26)] Check failed:
sequence_checker_.CalledOnValidSequencedThread(). WeakPtrs must be checked on
the same sequenced thread.

Commenting out that check then gets you to:

[12009:12077:0328/133048:FATAL:extension_garbage_collector.cc(232)] Check
failed: content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE). 

Reverting the patch fixes the issue.

Original issue's description:
> Remove ExtensionService Garbage-Collecting methods.
> 
> Make a new class, ExtensionGarbageCollector, which performs:
> - ExtensionService::GarbageCollectExtensions(),
> - extension_file_util::GarbageCollectExtensions() (the file-thread impl of
>   ExtensionService::GarbageCollectExtensions()),
> - ExtensionService::GarbageCollectIsolatedStorage()
> 
> BUG=351891
> TBR=rkc@chromium.org (for c/b/chromeos/kiosk_mode - no functional changes, but the TODO has moved from ExtensionService to ExtensionGarbageCollector).
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=260207

TBR=yoz@chromium.org,jyasskin@chromium.org,rkc@chromium.org,rdevlin.cronin@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=351891

Review URL: https://codereview.chromium.org/217233004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260265 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 83 insertions, 3 deletions

diff --git a/chrome/common/extensions/extension_file_util.cc b/chrome/common/extensions/extension_file_util.cc
index 814dde5..f186053 100644
--- a/chrome/common/extensions/extension_file_util.cc
+++ b/chrome/common/extensions/extension_file_util.cc
@@ -9,6 +9,7 @@
 
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
+#include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/logging.h"
@@ -44,6 +45,8 @@ namespace errors = extensions::manifest_errors;
 
 namespace {
 
+const base::FilePath::CharType kTempDirectoryName[] = FILE_PATH_LITERAL("Temp");
+
 // Add the image paths contained in the |icon_set| to |image_paths|.
 void AddPathsFromIconSet(const ExtensionIconSet& icon_set,
                          std::set<base::FilePath>* image_paths) {
@@ -59,8 +62,6 @@ void AddPathsFromIconSet(const ExtensionIconSet& icon_set,
 
 namespace extension_file_util {
 
-const base::FilePath::CharType kTempDirectoryName[] = FILE_PATH_LITERAL("Temp");
-
 base::FilePath InstallExtension(const base::FilePath& unpacked_source_dir,
                                 const std::string& id,
                                 const std::string& version,
@@ -121,7 +122,7 @@ void UninstallExtension(const base::FilePath& extensions_dir,
                         const std::string& id) {
   // We don't care about the return value. If this fails (and it can, due to
   // plugins that aren't unloaded yet), it will get cleaned up by
-  // ExtensionGarbageCollector::GarbageCollectExtensions.
+  // ExtensionService::GarbageCollectExtensions.
   base::DeleteFile(extensions_dir.AppendASCII(id), true);  // recursive.
 }
 
@@ -322,6 +323,85 @@ std::set<base::FilePath> GetBrowserImagePaths(const Extension* extension) {
   return image_paths;
 }
 
+void GarbageCollectExtensions(
+    const base::FilePath& install_directory,
+    const std::multimap<std::string, base::FilePath>& extension_paths,
+    bool clean_temp_dir) {
+  // Nothing to clean up if it doesn't exist.
+  if (!base::DirectoryExists(install_directory))
+    return;
+
+  DVLOG(1) << "Garbage collecting extensions...";
+  base::FileEnumerator enumerator(install_directory,
+                                  false,  // Not recursive.
+                                  base::FileEnumerator::DIRECTORIES);
+  base::FilePath extension_path;
+  for (extension_path = enumerator.Next(); !extension_path.value().empty();
+       extension_path = enumerator.Next()) {
+    std::string extension_id;
+
+    base::FilePath basename = extension_path.BaseName();
+    // Clean up temporary files left if Chrome crashed or quit in the middle
+    // of an extension install.
+    if (basename.value() == kTempDirectoryName) {
+      if (clean_temp_dir)
+        base::DeleteFile(extension_path, true);  // Recursive
+      continue;
+    }
+
+    // Parse directory name as a potential extension ID.
+    if (IsStringASCII(basename.value())) {
+      extension_id = base::UTF16ToASCII(basename.LossyDisplayName());
+      if (!Extension::IdIsValid(extension_id))
+        extension_id.clear();
+    }
+
+    // Delete directories that aren't valid IDs.
+    if (extension_id.empty()) {
+      DLOG(WARNING) << "Invalid extension ID encountered in extensions "
+                       "directory: " << basename.value();
+      DVLOG(1) << "Deleting invalid extension directory "
+               << extension_path.value() << ".";
+      base::DeleteFile(extension_path, true);  // Recursive.
+      continue;
+    }
+
+    typedef std::multimap<std::string, base::FilePath>::const_iterator Iter;
+    std::pair<Iter, Iter> iter_pair = extension_paths.equal_range(extension_id);
+
+    // If there is no entry in the prefs file, just delete the directory and
+    // move on. This can legitimately happen when an uninstall does not
+    // complete, for example, when a plugin is in use at uninstall time.
+    if (iter_pair.first == iter_pair.second) {
+      DVLOG(1) << "Deleting unreferenced install for directory "
+               << extension_path.LossyDisplayName() << ".";
+      base::DeleteFile(extension_path, true);  // Recursive.
+      continue;
+    }
+
+    // Clean up old version directories.
+    base::FileEnumerator versions_enumerator(
+        extension_path,
+        false,  // Not recursive.
+        base::FileEnumerator::DIRECTORIES);
+    for (base::FilePath version_dir = versions_enumerator.Next();
+         !version_dir.value().empty();
+         version_dir = versions_enumerator.Next()) {
+      bool knownVersion = false;
+      for (Iter it = iter_pair.first; it != iter_pair.second; ++it)
+        if (version_dir.BaseName() == it->second.BaseName()) {
+          knownVersion = true;
+          break;
+        }
+      if (!knownVersion) {
+        DVLOG(1) << "Deleting old version for directory "
+                 << version_dir.LossyDisplayName() << ".";
+        base::DeleteFile(version_dir, true);  // Recursive.
+      }
+    }
+  }
+}
+
 extensions::MessageBundle* LoadMessageBundle(
     const base::FilePath& extension_path,
     const std::string& default_locale,