Add FakeDisplaySnapshot builder and related changes.

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[,]
-//     H: display height in pixels
-//     W: display width in pixels
+//   HxW[^dpi][,]
+//     H: display height in pixels [int]
+//     W: display width in pixels [int]
+//     dpi: display physical size set based on DPI [int]
 //
 // Two 800x800 displays:
 //  --screen-config=800x800,800x800
 // One 1820x1080 display and one 400x400 display:
 //  --screen-config=1920x1080,400x400
+// 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;
 
   // FakeDisplayController:
   int64_t AddDisplay(const gfx::Size& display_size) override;
+  bool AddDisplay(std::unique_ptr<ui::DisplaySnapshot> display) override;
   bool RemoveDisplay(int64_t display_id) override;
 
   // NativeDisplayDelegate overrides:
   void Initialize() override;
   void GrabServer() override;
   void UngrabServer() override;
   void TakeDisplayControl(const ui::DisplayControlCallback& callback) override;
   void RelinquishDisplayControl(
       const ui::DisplayControlCallback& callback) override;
   void SyncWithServer() override;
@@ skipping 19 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:
-  // Initializes display snapshots from command line flags if provided.
-  void InitFromCommandLine();
+  // 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<FakeDisplaySnapshot>> displays_;
+  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_