Changes how to compute the id of a display.

chromeos/display/output_util.h

 // Copyright (c) 2013 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 CHROMEOS_DISPLAY_OUTPUT_UTIL_H_
 #define CHROMEOS_DISPLAY_OUTPUT_UTIL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "chromeos/chromeos_export.h"
 
 // Forward declarations for Xlib and Xrandr.
 // This is so unused X definitions don't pollute the namespace.
 typedef unsigned long XID;
 
 namespace chromeos {
 
-// Generates the display id for the pair of |output| and |index| and store
-// in |display_id_out|. Returns true if the display id is successfully
-// generated, or false otherwise.
+// Gets the EDID data from |output| and generates the display id through
+// |GetDisplayIdFromEDID|.
 CHROMEOS_EXPORT bool GetDisplayId(XID output, size_t index,
                                   int64* display_id_out);
 
+// Generates the display id for the pair of |prop| with |nitems| length and
+// |index|, and store in |display_id_out|. Returns true if the display id is
+// successfully generated, or false otherwise.
+CHROMEOS_EXPORT bool GetDisplayIdFromEDID(const unsigned char* prop,
+                                          unsigned long nitems,
+                                          size_t index,
+                                          int64* display_id_out);
+
 // Generates the human readable string from EDID obtained for |output|.
 CHROMEOS_EXPORT std::string GetDisplayName(XID output);
 
 // Gets the overscan flag from |output| and stores to |flag|. Returns true if
 // the flag is found. Otherwise returns false and doesn't touch |flag|. The
 // output will produce overscan if |flag| is set to true, but the output may
 // still produce overscan even though it returns true and |flag| is set to
 // false.
 CHROMEOS_EXPORT bool GetOutputOverscanFlag(XID output, bool* flag);
 
@@ skipping 12 matching lines @@
 CHROMEOS_EXPORT bool ParseOutputOverscanFlag(const unsigned char* prop,
                                              unsigned long nitems,
                                              bool* flag);
 
 // Returns true if an output named |name| is an internal display.
 CHROMEOS_EXPORT bool IsInternalOutputName(const std::string& name);
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DISPLAY_OUTPUT_UTIL_H_