Add ability to set resolution on external 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;
+typedef XID RRMode;
+struct _XRRModeInfo;
+typedef _XRRModeInfo XRRModeInfo;
+struct _XRRScreenResources;
+typedef _XRRScreenResources XRRScreenResources;
+struct _XRROutputInfo;
+typedef _XRROutputInfo XRROutputInfo;
 
 namespace chromeos {
 
 // 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
@@ skipping 24 matching lines @@
 
 // Parses |prop| as EDID data and stores the overscan flag to |flag|. Returns
 // true if the flag is found. This is exported for x11_util_unittest.cc.
 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);
 
+// Find a XRRModeInfo that matches |mode|.
+CHROMEOS_EXPORT const XRRModeInfo* FindModeInfo(
+    const XRRScreenResources* screen_resources,
+    XID mode);
+
+// Find a mode that matches the given size with highest refresh
+// rate. Non-interlaced mode takes precedence, so non-interlaced mode
+// with a lower refresh rate will be used even if there is an interlaced
+// mode with a higher refresh rate.
+CHROMEOS_EXPORT RRMode FindOutputModeMatchingSize(
+    const XRRScreenResources* screen_resources,
+    const XRROutputInfo* output_info,
+    size_t width,
+    size_t height);
+
+namespace test {
+
+// Creates XRRModeInfo for unit tests.
+CHROMEOS_EXPORT XRRModeInfo CreateModeInfo(int id,
+                                           int width,
+                                           int height,
+                                           bool interlaced,
+                                           float refresh_rate);
+
+}  // namespace test
+
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DISPLAY_OUTPUT_UTIL_H_