Read EDID for the 1st display for startup

ui/display/util/edid_parser.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 UI_DISPLAY_UTIL_EDID_PARSER_H_
 #define UI_DISPLAY_UTIL_EDID_PARSER_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "ui/display/util/display_util_export.h"
 
+namespace gfx {
+class Size;
+}
+
 // EDID (Extended Display Identification Data) is a format for monitor
 // metadata. This provides a parser for the data.
 
 namespace ui {
 
 // Generates the display id for the pair of |edid| and |index|, and store in
 // |display_id_out|. Returns true if the display id is successfully generated,
 // or false otherwise.
 DISPLAY_UTIL_EXPORT bool GetDisplayIdFromEDID(const std::vector<uint8_t>& edid,
                                               uint8_t index,
                                               int64_t* display_id_out);
 
-// Parses |edid| as EDID data and stores extracted data into |manufacturer_id|
-// and |human_readable_name| and returns true. NULL can be passed for unwanted
-// output parameters. Some devices (especially internal displays) may not have
-// the field for |human_readable_name|, and it will return true in that case.
-DISPLAY_UTIL_EXPORT bool ParseOutputDeviceData(
-    const std::vector<uint8_t>& edid,
-    uint16_t* manufacturer_id,
-    std::string* human_readable_name);
+// Parses |edid| as EDID data and stores extracted data into |manufacturer_id|,
+// |human_readable_name|, |pixel_out| and size_out, then returns true. NULL can

[dnicoara, 2015/01/16 20:39:51]

nit: |size_out|

[oshima, 2015/01/16 21:50:18]

Done.

+// be passed for unwanted output parameters. Some devices (especially internal
+// displays) may not have the field for |human_readable_name|, and it will
+// return true in that case.
+DISPLAY_UTIL_EXPORT bool ParseOutputDeviceData(const std::vector<uint8_t>& edid,
+                                               uint16_t* manufacturer_id,
+                                               std::string* human_readable_name,
+                                               gfx::Size* pixel_out,

[dnicoara, 2015/01/16 20:39:51]

nit: I think it would be clearer if |pixel_out| and |size_out| would have a more
expressive name (like mode_size and physical_display_size)

[oshima, 2015/01/16 21:50:18]

changed to active_pixel_out and physical_display_size_out (as described in
http://en.wikipedia.org/wiki/Extended_display_identification_data

+                                               gfx::Size* size_out);
 
 DISPLAY_UTIL_EXPORT bool ParseOutputOverscanFlag(
     const std::vector<uint8_t>& edid,
     bool* flag);
 
 }  // namespace ui
 
 #endif // UI_DISPLAY_UTIL_EDID_PARSER_H_