Add more options to --screen-config flag.

ui/display/fake_display_delegate.h

 // Copyright 2016 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_FAKE_DISPLAY_DELEGATE_H_
 #define UI_DISPLAY_FAKE_DISPLAY_DELEGATE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "ui/display/display_export.h"
 #include "ui/display/fake_display_snapshot.h"
 #include "ui/display/types/fake_display_controller.h"
 #include "ui/display/types/native_display_delegate.h"
 
 namespace display {
 
 // A NativeDisplayDelegate implementation that manages fake displays. Fake
 // displays mimic physical displays but do not actually exist. This is because
 // Chrome OS does not take over the entire display when running off device and
 // instead runs inside windows provided by the parent OS. Fake displays allow us
 // to simulate different connected display states off device and to test display
 // configuration and display management code.
 //
 // The size and number of displays can controlled via --screen-config=X
 // command line flag with the format:
-//   HxW[^dpi][,]
+//   HxW[%R][#HxW[%R][:HxW[%R]]][^D][/[a][c][i][o]][,...]

[Daniel Erat, 2016/10/05 21:09:45]

can you document what the #- and :-prefixed dimensions do? i take it from the
example below that '#' is used to list a second mode.

[kylechar, 2016/10/07 16:14:42]

Improved this comment a bunch I hope.

 //     H: display height in pixels [int]
 //     W: display width in pixels [int]
-//     dpi: display physical size set based on DPI [int]
+//     R: display refresh rate [float]
+//     D: display DPI, used to set physical size [int]
+//     Options:
+//      a: display is aspect preserving
+//      c: display has color correction matrix
+//      i: display is internal
+//      o: display has overscan
 //
-// Two 800x800 displays:
-//  --screen-config=800x800,800x800
-// One 1820x1080 display and one 400x400 display:
-//  --screen-config=1920x1080,400x400
+// Two 800x800 displays, with first display as internal display:
+//  --screen-config=800x800/i,800x800
+// One 1920x1080 display as internal display with alternate resolutions:
+//  --screen-config=1920x1080#1600x900:1280x720/i
+// One 1600x900 display with 120 refresh rate and high-DPI:
+//   --screen-config=1600x900%120^300
 // No displays:
 //  --screen-config=none
 //
 // FakeDisplayDelegate also implements FakeDisplayController which provides a
 // way to change the display state at runtime.
 class DISPLAY_EXPORT FakeDisplayDelegate : public ui::NativeDisplayDelegate,
                                            public FakeDisplayController {
  public:
   FakeDisplayDelegate();
   ~FakeDisplayDelegate() override;
@@ skipping 33 matching lines @@
       ui::ColorCalibrationProfile new_profile) override;
   bool SetColorCorrection(const ui::DisplaySnapshot& output,
                           const std::vector<ui::GammaRampRGBEntry>& degamma_lut,
                           const std::vector<ui::GammaRampRGBEntry>& gamma_lut,
                           const std::vector<float>& correction_matrix) override;
   void AddObserver(ui::NativeDisplayObserver* observer) override;
   void RemoveObserver(ui::NativeDisplayObserver* observer) override;
   FakeDisplayController* GetFakeDisplayController() override;
 
  protected:
-  // Creates a display snapshot from the provided |spec| string. Return null if
-  // |spec| is invalid.
-  std::unique_ptr<ui::DisplaySnapshot> CreateSnapshotFromSpec(
-      const std::string& spec);
-
   // Sets initial display snapshots from command line flag. Returns true if
   // command line flag was provided.
   bool InitFromCommandLine();
 
   // Updates observers when display configuration has changed. Will not update
   // until after |Initialize()| has been called.
   void OnConfigurationChanged();
 
  private:
   base::ObserverList<ui::NativeDisplayObserver> observers_;
   std::vector<std::unique_ptr<ui::DisplaySnapshot>> displays_;
 
   // If |Initialize()| has been called.
   bool initialized_ = false;
 
   // The next available display id.
   uint8_t next_display_id_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(FakeDisplayDelegate);
 };
 
 }  // namespace display
 #endif  // UI_DISPLAY_FAKE_DISPLAY_DELEGATE_H_