gdata: Change permissions of cache persistent directory.

chrome/browser/chromeos/gdata/gdata_file_system.cc

Index: chrome/browser/chromeos/gdata/gdata_file_system.cc
diff --git a/chrome/browser/chromeos/gdata/gdata_file_system.cc b/chrome/browser/chromeos/gdata/gdata_file_system.cc
index dd2ed256ae88be849e6c3baca1d3dc83fc6ca550..a8c7dc21ebe9f21879bc51324b1f04e10422f771 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system.cc
+++ b/chrome/browser/chromeos/gdata/gdata_file_system.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/chromeos/gdata/gdata_file_system.h"
 
 #include <errno.h>
+#include <sys/stat.h>
 
 #include <utility>
 
@@ -204,6 +205,22 @@ base::PlatformFileError CreateCacheDirectories(
   return error;
 }
 
+// Changes the permissions of |file_path| to |permissions|.
+// Returns the platform error code of the operation.
+base::PlatformFileError ChangeFilePermissions(const FilePath& file_path,
+                                              mode_t permissions) {
+  base::PlatformFileError error = base::PLATFORM_FILE_OK;
+
+  if (HANDLE_EINTR(chmod(file_path.value().c_str(), permissions)) != 0) {
+    error = SystemToPlatformError(errno);
+    PLOG(ERROR) << "Error changing permissions of " << file_path.value();
+  } else {
+    DVLOG(1) << "Changed permissions of " << file_path.value();
+  }
+
+  return error;
+}
+
 // Modifies cache state of file on IO thread pool, which involves:
 // - moving or copying file (per |file_operation_type|) from |source_path| to
 //  |dest_path| if they're different
@@ -3249,7 +3266,14 @@ void GDataFileSystem::InitializeCacheIfNecessary() {
 
 void GDataFileSystem::InitializeCacheOnIOThreadPool() {
   base::PlatformFileError error = CreateCacheDirectories(cache_paths_);
+  if (error != base::PLATFORM_FILE_OK)
+    return;
 
+  // Change permissions of cache persistent directory to u+rwx,og+x in order to
+  // allow archive files in that directory to be mounted by cros-disks.
+  error = ChangeFilePermissions(
+      cache_paths_[GDataRootDirectory::CACHE_TYPE_PERSISTENT],
+      S_IRWXU | S_IXGRP | S_IXOTH);
   if (error != base::PLATFORM_FILE_OK)
     return;