Do PPB_FileIO Query and Read in the plugin process.

ppapi/shared_impl/tracked_callback.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PPAPI_SHARED_IMPL_TRACKED_CALLBACK_H_
 #define PPAPI_SHARED_IMPL_TRACKED_CALLBACK_H_
 
 #include <map>
 #include <set>
 
@@ skipping 80 matching lines @@
   PP_Resource resource_id() const { return resource_id_; }
 
   // Returns true if the callback was completed (possibly aborted).
   bool completed() const { return completed_; }
 
   // Returns true if the callback was or should be aborted; this will be the
   // case whenever |Abort()| or |PostAbort()| is called before a non-abortive
   // completion.
   bool aborted() const { return aborted_; }
 
+  // Returns true if this is a blocking callback.
+  bool is_blocking() {
+    return !callback_.func;
+  }
+
   // Determines if the given callback is pending. A callback is pending if it
   // has not completed and has not been aborted. When receiving a plugin call,
   // use this to detect if |callback| represents an operation in progress. When
   // finishing a plugin call, use this to determine whether to write 'out'
   // params and Run |callback|.
   // NOTE: an aborted callback has not necessarily completed, so a false result
   // doesn't imply that the callback has completed.
   // As a convenience, if |callback| is null, this returns false.
   static bool IsPending(const scoped_refptr<TrackedCallback>& callback);
 
   // Helper to determine if the given callback is scheduled to run on another
   // message loop.
   static bool IsScheduledToRun(const scoped_refptr<TrackedCallback>& callback);
 
  protected:
-  bool is_blocking() {
-    return !callback_.func;
-  }
-
   bool is_required() {
     return (callback_.func &&
             !(callback_.flags & PP_COMPLETIONCALLBACK_FLAG_OPTIONAL));
   }
   bool is_optional() {
     return (callback_.func &&
             (callback_.flags & PP_COMPLETIONCALLBACK_FLAG_OPTIONAL));
   }
   bool has_null_target_loop() const { return target_loop_.get() == NULL; }
 
@@ skipping 35 matching lines @@
   // callback. Note that in-process, there is no lock, blocking callbacks are
   // not allowed, and therefore this pointer will be NULL.
   scoped_ptr<base::ConditionVariable> operation_completed_condvar_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(TrackedCallback);
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_TRACKED_CALLBACK_H_