Grant file access permissions for cached file paths to file browsers/handlers.

chrome/browser/chromeos/extensions/file_handler_util.cc

Index: chrome/browser/chromeos/extensions/file_handler_util.cc
diff --git a/chrome/browser/chromeos/extensions/file_handler_util.cc b/chrome/browser/chromeos/extensions/file_handler_util.cc
index 71c5fb18ecda384b719f65164458fbb1518b0ba1..5d51e1abbdf2ba90125708370ca496cdf4cb3020 100644
--- a/chrome/browser/chromeos/extensions/file_handler_util.cc
+++ b/chrome/browser/chromeos/extensions/file_handler_util.cc
@@ -11,6 +11,7 @@
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/chromeos/gdata/gdata_util.h"
 #include "chrome/browser/chromeos/extensions/file_manager_util.h"
 #include "chrome/browser/extensions/extension_event_router.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ -51,6 +52,10 @@ const int kReadWriteFilePermissions = base::PLATFORM_FILE_OPEN |
                                       base::PLATFORM_FILE_ASYNC |
                                       base::PLATFORM_FILE_WRITE_ATTRIBUTES;
 
+const int kReadOnlyFilePermissions = base::PLATFORM_FILE_OPEN |
+                                     base::PLATFORM_FILE_READ |
+                                     base::PLATFORM_FILE_EXCLUSIVE_READ |
+                                     base::PLATFORM_FILE_ASYNC;
 
 // Returns process id of the process the extension is running in.
 int ExtractProcessFromExtensionId(const std::string& extension_id,
@@ -168,6 +173,10 @@ int GetReadWritePermissions() {
   return kReadWriteFilePermissions;
 }
 
+int GetReadOnlyPermissions() {
+  return kReadOnlyFilePermissions;
+}
+
 std::string MakeTaskID(const std::string& extension_id,
                        const std::string& action_id) {
   return base::StringPrintf("%s|%s", extension_id.c_str(), action_id.c_str());
@@ -391,17 +400,17 @@ class FileTaskExecutor::ExecuteTasksFileSystemCallbackDispatcher {
     // Check if this file system entry exists first.
     base::PlatformFileInfo file_info;
 
-    if (!file_util::PathExists(final_file_path) ||
-        file_util::IsLink(final_file_path) ||
-        !file_util::GetFileInfo(final_file_path, &file_info))
-      return false;
+    bool is_gdata_file = gdata::util::IsUnderGDataMountPoint(final_file_path);
 
-    // TODO(zelidrag): Let's just prevent all symlinks for now. We don't want a
-    // USB drive content to point to something in the rest of the file system.
-    // Ideally, we should permit symlinks within the boundary of the same
-    // virtual mount point.
-    if (file_info.is_symbolic_link)
-      return false;
+    // If the file is under gdata mount point, there is no actual file to be
+    // found on the final_file_path.
+    if (!is_gdata_file) {
+      if (!file_util::PathExists(final_file_path) ||
+          file_util::IsLink(final_file_path) ||
+          !file_util::GetFileInfo(final_file_path, &file_info)) {
+        return false;
+      }
+    }
 
     // TODO(tbarzic): Add explicit R/W + R/O permissions for non-component
     // extensions.
@@ -413,6 +422,11 @@ class FileTaskExecutor::ExecuteTasksFileSystemCallbackDispatcher {
         final_file_path,
         GetReadWritePermissions());
 
+    if (is_gdata_file) {
+      gdata::util::SetPermissionsForGDataCacheFiles(profile_, handler_pid_,
+          final_file_path);
+    }
+
     // Grant access to this particular file to target extension. This will
     // ensure that the target extension can access only this FS entry and
     // prevent from traversing FS hierarchy upward.