Changes how to compute the id of a display.

chromeos/display/output_util.h

Index: chromeos/display/output_util.h
diff --git a/chromeos/display/output_util.h b/chromeos/display/output_util.h
index 5ecda9bf055a6d6b6c1bf23c612a637739c37c26..bfdb3c6982504c531625aace2c3261ef4d9b1481 100644
--- a/chromeos/display/output_util.h
+++ b/chromeos/display/output_util.h
@@ -16,12 +16,19 @@ 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);