Make HidConnection::Read reentrancy safe

device/hid/hid_connection.h

 // Copyright 2014 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 DEVICE_HID_HID_CONNECTION_H_
 #define DEVICE_HID_HID_CONNECTION_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 57 matching lines @@
   virtual void PlatformRead(const ReadCallback& callback) = 0;
   virtual void PlatformWrite(scoped_refptr<net::IOBuffer> buffer,
                              size_t size,
                              const WriteCallback& callback) = 0;
   virtual void PlatformGetFeatureReport(uint8_t report_id,
                                         const ReadCallback& callback) = 0;
   virtual void PlatformSendFeatureReport(scoped_refptr<net::IOBuffer> buffer,
                                          size_t size,
                                          const WriteCallback& callback) = 0;
 
-  // PlatformRead implementation must call this method on read
-  // success, rather than directly running the callback.
-  // In case incoming buffer is empty or protected, it is filtered
-  // and this method returns false. Otherwise it runs the callback
-  // and returns true.
-  bool CompleteRead(scoped_refptr<net::IOBuffer> buffer,
-                    size_t size,
-                    const ReadCallback& callback);
+  bool IsReportIdProtected(uint8_t report_id);
 
  private:
-  bool IsReportIdProtected(uint8_t report_id);
-
   scoped_refptr<HidDeviceInfo> device_info_;
   bool has_protected_collection_;
   base::ThreadChecker thread_checker_;
   bool closed_;
 
   DISALLOW_COPY_AND_ASSIGN(HidConnection);
 };
 
 struct PendingHidReport {
   PendingHidReport();
   PendingHidReport(const PendingHidReport& other);
   ~PendingHidReport();
 
   scoped_refptr<net::IOBuffer> buffer;
   size_t size;
 };
 
 struct PendingHidRead {
   PendingHidRead();
   PendingHidRead(const PendingHidRead& other);
   ~PendingHidRead();
 
   HidConnection::ReadCallback callback;
 };
 
 }  // namespace device
 
 #endif  // DEVICE_HID_HID_CONNECTION_H_