Checks the possibility of overscans from EDID extension data.

ui/base/x/x11_util.h

Index: ui/base/x/x11_util.h
diff --git a/ui/base/x/x11_util.h b/ui/base/x/x11_util.h
index e7169a6f0d1515dd2fdf21f95194dabb87292cb3..a5b8beccd9aa63077c5a657b8d0e220b45a0d02a 100644
--- a/ui/base/x/x11_util.h
+++ b/ui/base/x/x11_util.h
@@ -276,6 +276,25 @@ UI_EXPORT bool GetOutputDeviceData(XID output,
                                    uint32* serial_number,
                                    std::string* human_readable_name);
 
+// Returns true if the EDID for the output has the flag of overscan. Note that
+// returning false does not mean no overscan, it just means the lack of flag.
+UI_EXPORT bool HasOutputOverscanFlag(XID output);
+
+// Parses |prop| as EDID data and stores extracted data into |manufacturer_id|,
+// |serial_number|, and |human_readable_name| and returns true. This is exported
+// for x11_util_unittest.cc.
+UI_EXPORT bool ParseOutputDeviceData(const unsigned char* prop,
+                                     unsigned long nitems,
+                                     uint16* manufacturer_id,
+                                     uint32* serial_number,
+                                     std::string* human_readable_name);
+
+// Parses |prop| as EDID data and stores overscan flag to |flag|. Returns true
+// if the flag is found. This is exported for x11_util_unittest.cc.
+UI_EXPORT bool ParseOutputOverscanFlag(const unsigned char* prop,
+                                       unsigned long nitems,
+                                       bool* flag);
+
 // Gets the names of the all displays physically connected to the system.
 UI_EXPORT std::vector<std::string> GetDisplayNames(
     const std::vector<XID>& output_id);