Make Isolated file system writable only if it is configured so

webkit/fileapi/isolated_context.cc

Index: webkit/fileapi/isolated_context.cc
diff --git a/webkit/fileapi/isolated_context.cc b/webkit/fileapi/isolated_context.cc
index cc9e925585b2dc26c3543bc026f19e448954c0b2..b2e91aa538cb092354c04aadbd44d2023abf8417 100644
--- a/webkit/fileapi/isolated_context.cc
+++ b/webkit/fileapi/isolated_context.cc
@@ -51,6 +51,7 @@ void IsolatedContext::RevokeIsolatedFileSystem(
     const std::string& filesystem_id) {
   base::AutoLock locker(lock_);
   toplevel_map_.erase(filesystem_id);
+  writable_ids_.erase(filesystem_id);
 }
 
 bool IsolatedContext::CrackIsolatedPath(const FilePath& virtual_path,
@@ -97,7 +98,7 @@ bool IsolatedContext::CrackIsolatedPath(const FilePath& virtual_path,
   return true;
 }
 
-bool IsolatedContext::GetTopLevelPaths(std::string filesystem_id,
+bool IsolatedContext::GetTopLevelPaths(const std::string& filesystem_id,
                                        std::vector<FilePath>* paths) const {
   DCHECK(paths);
   base::AutoLock locker(lock_);
@@ -114,6 +115,23 @@ bool IsolatedContext::GetTopLevelPaths(std::string filesystem_id,
   return true;
 }
 
+bool IsolatedContext::SetWritable(const std::string& filesystem_id,
+                                  bool writable) {
+  base::AutoLock locker(lock_);
+  if (writable_ids_.find(filesystem_id) == writable_ids_.end())
+    return false;

[kinaba, 2012/06/08 04:40:19]

I failed to understand these two lines.
It looks like "if it is not writable right now, return false". Maybe something
other than writable_ids_ should be looked up?

[kinuko, 2012/06/08 05:24:25]

Aha you're right.  I was first writing this patch like permission_mask_map_ and
then revised it , but failed to update this line... (hmm maybe I need a test)

Fixed.

+  if (writable)
+    writable_ids_.insert(filesystem_id);
+  else
+    writable_ids_.erase(filesystem_id);
+  return true;
+}
+
+bool IsolatedContext::IsWritable(const std::string& filesystem_id) const {
+  base::AutoLock locker(lock_);
+  return (writable_ids_.find(filesystem_id) != writable_ids_.end());
+}
+
 FilePath IsolatedContext::CreateVirtualPath(
     const std::string& filesystem_id, const FilePath& relative_path) const {
   FilePath full_path;