Eliminate usage of InterfacePtr::WaitForIncomingResponse.

components/filesystem/public/interfaces/file.mojom

Index: components/filesystem/public/interfaces/file.mojom
diff --git a/components/filesystem/public/interfaces/file.mojom b/components/filesystem/public/interfaces/file.mojom
index 6ef7067690235083499b09886c5f6d25494a24f0..05bce45cbf2b2db5076f8fd9f6ff7dac0729f322 100644
--- a/components/filesystem/public/interfaces/file.mojom
+++ b/components/filesystem/public/interfaces/file.mojom
@@ -16,6 +16,7 @@ interface File {
   // Flushes/closes this file; no operations may be performed on this file after
   // this. Note that any error code is strictly informational -- the close may
   // not be retried.
+  [Sync]
   Close() => (FileError err);
 
   // Reads (at most) |num_bytes_to_read| from the location specified by
@@ -24,42 +25,51 @@ interface File {
   // are read.
   // TODO(vtl): Clarify when (for what values of |offset|/|whence|) this
   // modifies the file position. Or maybe there should be a flag?
+  [Sync]
   Read(uint32 num_bytes_to_read, int64 offset, Whence whence)
       => (FileError error, array<uint8>? bytes_read);
 
   // Writes |bytes_to_write| to the location specified by |offset|/|whence|.
   // TODO(vtl): Clarify behavior when |num_bytes_written| is less than the size
   // of |bytes_to_write|.
+  [Sync]
   Write(array<uint8> bytes_to_write, int64 offset, Whence whence)
       => (FileError error, uint32 num_bytes_written);
 
   // Gets the current file position. On success, |position| is the current
   // offset (in bytes) from the beginning of the file).
+  [Sync]
   Tell() => (FileError error, int64 position);
 
   // Sets the current file position to that specified by |offset|/|whence|. On
   // success, |position| is the offset (in bytes) from the beginning of the
   // file.
+  [Sync]
   Seek(int64 offset, Whence whence) => (FileError error, int64 position);
 
   // Gets information about this file. On success, |file_information| is
   // non-null and will contain this information.
+  [Sync]
   Stat() => (FileError error, FileInformation? file_information);
 
   // Truncates this file to the size specified by |size| (in bytes).
+  [Sync]
   Truncate(int64 size) => (FileError error);
 
   // Updates this file's atime and/or mtime to the time specified by |atime| (or
   // |mtime|, respectively), which may also indicate "now". If |atime| or
   // |mtime| is null, then the corresponding time is not modified.
+  [Sync]
   Touch(TimespecOrNow? atime, TimespecOrNow? mtime) => (FileError error);
 
   // Creates a new |File| instance, which shares the same "file description".
   // I.e., the access mode, etc. (as specified to |Directory::OpenFile()| by the
   // |open_flags| argument) as well as file position.
+  [Sync]
   Dup(File& file) => (FileError error);
 
   // Syncs data to disk.
+  [Sync]
   Flush() => (FileError error);
 
   // Attempts to take an exclusive write lock on the file. This both takes a
@@ -73,5 +83,6 @@ interface File {
   Unlock() => (FileError error);
 
   // Returns a handle to the file for raw access.
+  [Sync]
   AsHandle() => (FileError error, handle file_handle);
 };