multi-display-mirroring: Prerequisite clean up

This CL is a prerequisite CL for supporting mirroring across 3+
displays.
Changes:
1. Clean up old code of mirror mode in display manager and make software
and hardware mirroring more intuitive.
2. Fix a bug that misuses mirroring destination display as source in
display_info_provider_chromeos.cc

Design doc:
go/multi-display-mirroring

BUG=607844

Change-Id: I38a065e2693c1094d9b460dd99ad0b2daabd0215
Reviewed-on: https://chromium-review.googlesource.com/734799Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512867}

ash/display/cursor_window_controller.cc

@@ -150,13 +150,16 @@ void CursorWindowController::UpdateContainer() {
     if (display.is_valid())
       SetDisplay(display);
   } else {
-    aura::Window* mirror_window = Shell::Get()
-                                      ->window_tree_host_manager()
-                                      ->mirror_window_controller()
-                                      ->GetWindow();
-    if (mirror_window)
-      display_ = display::Screen::GetScreen()->GetPrimaryDisplay();
-    SetContainer(mirror_window);
+    aura::Window::Windows mirror_windows = Shell::Get()
+                                               ->window_tree_host_manager()
+                                               ->mirror_window_controller()
+                                               ->GetAllRootWindows();
+    if (mirror_windows.empty()) {
+      SetContainer(nullptr);
+      return;
+    }
+    display_ = display::Screen::GetScreen()->GetPrimaryDisplay();
+    SetContainer(mirror_windows[0]);
   }
   // Updates the hot point based on the current display.
   UpdateCursorImage();

ash/display/display_manager_unittest.cc

@@ -1350,7 +1350,7 @@ TEST_F(DisplayManagerTest, TestNativeDisplaysChanged) {
   EXPECT_EQ("0,0 500x500",
             GetDisplayForId(internal_display_id).bounds().ToString());
   EXPECT_EQ(2U, display_manager()->num_connected_displays());
-  EXPECT_EQ(11U, display_manager()->mirroring_display_id());
+  EXPECT_EQ(11U, display_manager()->GetMirroringDstDisplayIdList()[0]);
   EXPECT_TRUE(display_manager()->IsInMirrorMode());
 
   // Test display name.
@@ -2147,13 +2147,13 @@ class TestDisplayObserver : public display::DisplayObserver {
   void OnDisplayAdded(const display::Display& new_display) override {
     // Mirror window should already be delete before restoring
     // the external display.
-    EXPECT_FALSE(test_api.GetHost());
+    EXPECT_TRUE(test_api.GetHosts().empty());
     changed_ = true;
   }
   void OnDisplayRemoved(const display::Display& old_display) override {
     // Mirror window should not be created until the external display
     // is removed.
-    EXPECT_FALSE(test_api.GetHost());
+    EXPECT_TRUE(test_api.GetHosts().empty());
     changed_ = true;
   }
 
@@ -2174,7 +2174,7 @@ TEST_F(DisplayManagerTest, SoftwareMirroring) {
   UpdateDisplay("300x400,400x500");
 
   MirrorWindowTestApi test_api;
-  EXPECT_EQ(nullptr, test_api.GetHost());
+  EXPECT_TRUE(test_api.GetHosts().empty());
 
   TestDisplayObserver display_observer;
   display::Screen::GetScreen()->AddObserver(&display_observer);
@@ -2187,15 +2187,15 @@ TEST_F(DisplayManagerTest, SoftwareMirroring) {
   EXPECT_EQ(
       "0,0 300x400",
       display::Screen::GetScreen()->GetPrimaryDisplay().bounds().ToString());
-  EXPECT_EQ("400x500",
-            test_api.GetHost()->GetBoundsInPixels().size().ToString());
-  EXPECT_EQ("300x400",
-            test_api.GetHost()->window()->bounds().size().ToString());
+  std::vector<aura::WindowTreeHost*> hosts = test_api.GetHosts();
+  EXPECT_EQ(1U, hosts.size());
+  EXPECT_EQ("400x500", hosts[0]->GetBoundsInPixels().size().ToString());
+  EXPECT_EQ("300x400", hosts[0]->window()->bounds().size().ToString());
   EXPECT_TRUE(display_manager()->IsInMirrorMode());
 
   display_manager()->SetMirrorMode(false);
   EXPECT_TRUE(display_observer.changed_and_reset());
-  EXPECT_EQ(nullptr, test_api.GetHost());
+  EXPECT_TRUE(test_api.GetHosts().empty());
   EXPECT_EQ(2U, display_manager()->GetNumDisplays());
   EXPECT_FALSE(display_manager()->IsInMirrorMode());
 
@@ -2207,28 +2207,28 @@ TEST_F(DisplayManagerTest, SoftwareMirroring) {
   UpdateDisplay("300x400@0.5,400x500");
   EXPECT_FALSE(display_observer.changed_and_reset());
   EXPECT_EQ("300x400",
-            test_api.GetHost()->window()->bounds().size().ToString());
+            test_api.GetHosts()[0]->window()->bounds().size().ToString());
 
   UpdateDisplay("310x410*2,400x500");
   EXPECT_FALSE(display_observer.changed_and_reset());
   EXPECT_EQ("310x410",
-            test_api.GetHost()->window()->bounds().size().ToString());
+            test_api.GetHosts()[0]->window()->bounds().size().ToString());
 
   UpdateDisplay("320x420/r,400x500");
   EXPECT_FALSE(display_observer.changed_and_reset());
   EXPECT_EQ("320x420",
-            test_api.GetHost()->window()->bounds().size().ToString());
+            test_api.GetHosts()[0]->window()->bounds().size().ToString());
 
   UpdateDisplay("330x440/r,400x500");
   EXPECT_FALSE(display_observer.changed_and_reset());
   EXPECT_EQ("330x440",
-            test_api.GetHost()->window()->bounds().size().ToString());
+            test_api.GetHosts()[0]->window()->bounds().size().ToString());
 
   // Overscan insets are ignored.
   UpdateDisplay("400x600/o,600x800/o");
   EXPECT_FALSE(display_observer.changed_and_reset());
   EXPECT_EQ("400x600",
-            test_api.GetHost()->window()->bounds().size().ToString());
+            test_api.GetHosts()[0]->window()->bounds().size().ToString());
 
   display::Screen::GetScreen()->RemoveObserver(&display_observer);
 }
@@ -2255,14 +2255,16 @@ TEST_F(DisplayManagerTest, SingleDisplayToSoftwareMirroring) {
   EXPECT_EQ(1U, display_manager()->GetNumDisplays());
   WindowTreeHostManager* window_tree_host_manager =
       ash::Shell::Get()->window_tree_host_manager();
-  EXPECT_TRUE(
-      window_tree_host_manager->mirror_window_controller()->GetWindow());
+  EXPECT_EQ(1U, window_tree_host_manager->mirror_window_controller()
+                    ->GetAllRootWindows()
+                    .size());
 
   UpdateDisplay("600x400");
   EXPECT_FALSE(display_manager()->IsInMirrorMode());
   EXPECT_EQ(1U, display_manager()->GetNumDisplays());
-  EXPECT_FALSE(
-      window_tree_host_manager->mirror_window_controller()->GetWindow());
+  EXPECT_TRUE(window_tree_host_manager->mirror_window_controller()
+                  ->GetAllRootWindows()
+                  .empty());
 }
 
 // Make sure this does not cause any crashes. See http://crbug.com/412910
@@ -2270,7 +2272,7 @@ TEST_F(DisplayManagerTest, SoftwareMirroringWithCompositingCursor) {
   UpdateDisplay("300x400,400x500");
 
   MirrorWindowTestApi test_api;
-  EXPECT_EQ(nullptr, test_api.GetHost());
+  EXPECT_TRUE(test_api.GetHosts().empty());
 
   display::ManagedDisplayInfo secondary_info =
       display_manager()->GetDisplayInfo(

ash/display/mirror_window_controller.cc

@@ -315,16 +315,6 @@ void MirrorWindowController::OnHostResized(aura::WindowTreeHost* host) {
   }
 }
 
-aura::Window* MirrorWindowController::GetWindow() {
-  display::DisplayManager* display_manager = Shell::Get()->display_manager();
-  if (!display_manager->IsInMirrorMode() || mirroring_host_info_map_.empty())
-    return nullptr;
-  DCHECK_EQ(1U, mirroring_host_info_map_.size());
-  return mirroring_host_info_map_.begin()
-      ->second->ash_host->AsWindowTreeHost()
-      ->window();
-}
-
 display::Display MirrorWindowController::GetDisplayForRootWindow(
     const aura::Window* root) const {
   for (const auto& pair : mirroring_host_info_map_) {

ash/display/mirror_window_controller.h

@@ -64,10 +64,6 @@ class ASH_EXPORT MirrorWindowController : public aura::WindowTreeHostObserver {
   // aura::WindowTreeHostObserver overrides:
   void OnHostResized(aura::WindowTreeHost* host) override;
 
-  // Return the root window used to mirror the content. NULL if the
-  // display is not mirrored by the compositor path.
-  aura::Window* GetWindow();
-
   // Returns the display::Display for the mirroring root window.
   display::Display GetDisplayForRootWindow(const aura::Window* root) const;
 

ash/display/mirror_window_controller_unittest.cc

@@ -259,7 +259,7 @@ TEST_F(MirrorWindowControllerTest, DockMode) {
 
   EXPECT_EQ(1U, display_manager()->GetNumDisplays());
   EXPECT_TRUE(display_manager()->IsInMirrorMode());
-  EXPECT_EQ(external_id, display_manager()->mirroring_display_id());
+  EXPECT_EQ(external_id, display_manager()->GetMirroringDstDisplayIdList()[0]);
 
   // dock mode.
   display_info_list.clear();
@@ -277,14 +277,14 @@ TEST_F(MirrorWindowControllerTest, DockMode) {
   display_manager()->OnNativeDisplaysChanged(display_info_list);
   EXPECT_EQ(1U, display_manager()->GetNumDisplays());
   EXPECT_TRUE(display_manager()->IsInMirrorMode());
-  EXPECT_EQ(external_id, display_manager()->mirroring_display_id());
+  EXPECT_EQ(external_id, display_manager()->GetMirroringDstDisplayIdList()[0]);
 }
 
 TEST_F(MirrorOnBootTest, MirrorOnBoot) {
   EXPECT_TRUE(display_manager()->IsInMirrorMode());
   RunAllPendingInMessageLoop();
   MirrorWindowTestApi test_api;
-  EXPECT_TRUE(test_api.GetHost());
+  EXPECT_EQ(1U, test_api.GetHosts().size());
 }
 
 }  // namespace ash

ash/display/mirror_window_test_api.cc

@@ -14,12 +14,15 @@
 
 namespace ash {
 
-const aura::WindowTreeHost* MirrorWindowTestApi::GetHost() const {
-  aura::Window* window = Shell::Get()
-                             ->window_tree_host_manager()
-                             ->mirror_window_controller()
-                             ->GetWindow();
-  return window ? window->GetHost() : NULL;
+std::vector<aura::WindowTreeHost*> MirrorWindowTestApi::GetHosts() const {
+  std::vector<aura::WindowTreeHost*> hosts;
+  for (auto* window : Shell::Get()
+                          ->window_tree_host_manager()
+                          ->mirror_window_controller()
+                          ->GetAllRootWindows()) {
+    hosts.emplace_back(window->GetHost());
+  }
+  return hosts;
 }
 
 ui::CursorType MirrorWindowTestApi::GetCurrentCursorType() const {

ash/display/mirror_window_test_api.h

@@ -5,6 +5,8 @@
 #ifndef ASH_DISPLAY_MIRROR_WINDOW_TEST_API_H_
 #define ASH_DISPLAY_MIRROR_WINDOW_TEST_API_H_
 
+#include <vector>
+
 #include "base/macros.h"
 
 namespace aura {
@@ -27,7 +29,7 @@ class MirrorWindowTestApi {
   MirrorWindowTestApi() {}
   ~MirrorWindowTestApi() {}
 
-  const aura::WindowTreeHost* GetHost() const;
+  std::vector<aura::WindowTreeHost*> GetHosts() const;
 
   ui::CursorType GetCurrentCursorType() const;
 

ash/display/root_window_transformers_unittest.cc

@@ -127,7 +127,7 @@ class RootWindowTransformersTest : public AshTestBase {
     DCHECK(display_manager()->IsInMirrorMode());
     const display::ManagedDisplayInfo& mirror_display_info =
         display_manager()->GetDisplayInfo(
-            display_manager()->mirroring_display_id());
+            display_manager()->GetMirroringDstDisplayIdList()[0]);
     const display::ManagedDisplayInfo& source_display_info =
         display_manager()->GetDisplayInfo(
             display::Screen::GetScreen()->GetPrimaryDisplay().id());

ash/system/screen_layout_observer.cc

@@ -51,18 +51,21 @@ base::string16 GetDisplayName(int64_t display_id) {
 base::string16 GetDisplaySize(int64_t display_id) {
   display::DisplayManager* display_manager = GetDisplayManager();
 
-  const display::Display* display =
-      &display_manager->GetDisplayForId(display_id);
-
   // We don't show display size for mirrored display. Fallback
   // to empty string if this happens on release build.
-  bool mirroring = display_manager->mirroring_display_id() == display_id;
+  const display::DisplayIdList id_list =
+      display_manager->GetMirroringDstDisplayIdList();
+  const bool mirroring =
+      display_manager->IsInMirrorMode() &&
+      std::find(id_list.begin(), id_list.end(), display_id) != id_list.end();
   DCHECK(!mirroring);
   if (mirroring)
     return base::string16();
 
-  DCHECK(display->is_valid());
-  return base::UTF8ToUTF16(display->size().ToString());
+  const display::Display& display =
+      display_manager->GetDisplayForId(display_id);
+  DCHECK(display.is_valid());
+  return base::UTF8ToUTF16(display.size().ToString());
 }
 
 // Callback to handle a user selecting the notification view.
@@ -131,10 +134,11 @@ bool IsDockedModeEnabled() {
 // Returns the notification message that should be shown when mirror display
 // mode is entered.
 base::string16 GetEnterMirrorModeMessage() {
+  DCHECK(GetDisplayManager()->IsInMirrorMode());
   if (display::Display::HasInternalDisplay()) {
     return l10n_util::GetStringFUTF16(
         IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING,
-        GetDisplayName(GetDisplayManager()->mirroring_display_id()));
+        GetDisplayName(GetDisplayManager()->GetMirroringDstDisplayIdList()[0]));
   }
 
   return l10n_util::GetStringUTF16(

ash/system/screen_layout_observer_unittest.cc

@@ -97,8 +97,9 @@ base::string16 ScreenLayoutObserverTest::GetSecondDisplayName() {
 }
 
 base::string16 ScreenLayoutObserverTest::GetMirroringDisplayName() {
+  DCHECK(display_manager()->IsInMirrorMode());
   return base::UTF8ToUTF16(display_manager()->GetDisplayNameForId(
-      display_manager()->mirroring_display_id()));
+      display_manager()->GetMirroringDstDisplayIdList()[0]));
 }
 
 const message_center::Notification*

chrome/browser/extensions/display_info_provider_chromeos.cc

@@ -610,7 +610,7 @@ void DisplayInfoProviderChromeOS::UpdateDisplayUnitInfoForPlatform(
   unit->name = display_manager->GetDisplayNameForId(display.id());
   if (display_manager->IsInMirrorMode()) {
     unit->mirroring_source_id =
-        base::Int64ToString(display_manager->mirroring_display_id());
+        base::Int64ToString(display_manager->mirroring_source_id());
   }
 
   const display::ManagedDisplayInfo& display_info =

chrome/browser/extensions/display_info_provider_chromeos_unittest.cc

@@ -531,7 +531,7 @@ TEST_F(DisplayInfoProviderChromeosTest, GetMirroring) {
 
   ASSERT_EQ(1u, result.size());
   EXPECT_EQ(base::Int64ToString(display_id_primary), result[0].id);
-  EXPECT_EQ(base::Int64ToString(display_id_secondary),
+  EXPECT_EQ(base::Int64ToString(display_id_primary),
             result[0].mirroring_source_id);
 
   GetDisplayManager()->SetMirrorMode(false);

ui/display/manager/chromeos/display_configurator.h

@@ -110,6 +110,9 @@ class DISPLAY_MANAGER_EXPORT DisplayConfigurator
 
     // Called when the hardware mirroring failed.
     virtual void SetSoftwareMirroring(bool enabled) = 0;
+
+    // Returns true when software mirroring mode is requested, but it does
+    // not guarantee that the mode is active.
     virtual bool SoftwareMirroringEnabled() const = 0;
   };
 

ui/display/manager/display_manager.h

@@ -289,13 +289,31 @@ class DISPLAY_MANAGER_EXPORT DisplayManager
   // mirrored.
   size_t num_connected_displays() const { return num_connected_displays_; }
 
-  // Returns the mirroring status.
+  // Returns true if either software or hardware mirror mode is active.
   bool IsInMirrorMode() const;
-  int64_t mirroring_display_id() const { return mirroring_display_id_; }
+
+  // Returns true if software mirror mode is active. Note that when
+  // SoftwareMirroringEnabled() returns true, it only means software mirroring
+  // mode is requested, but it does not guarantee that the mode is active. The
+  // mode will be active after UpdateDisplaysWith() is called.
+  bool IsInSoftwareMirrorMode() const;
+
+  // Returns true if hardware mirror mode is active.
+  bool IsInHardwareMirrorMode() const;
+
+  int64_t mirroring_source_id() const { return mirroring_source_id_; }
+
+  // Returns a list of mirroring destination display ids.
+  DisplayIdList GetMirroringDstDisplayIdList() const;
+
   const Displays& software_mirroring_display_list() const {
     return software_mirroring_display_list_;
   }
 
+  // Remove mirroring source and destination displays, so that they will be
+  // updated when UpdateDisplaysWith() is called.
+  void ClearMirroringSourceAndDestination();
+
   // Sets/gets if the unified desktop feature is enabled.
   void SetUnifiedDesktopEnabled(bool enabled);
   bool unified_desktop_enabled() const { return unified_desktop_enabled_; }
@@ -408,10 +426,6 @@ class DISPLAY_MANAGER_EXPORT DisplayManager
     DISALLOW_COPY_AND_ASSIGN(BeginEndNotifier);
   };
 
-  bool software_mirroring_enabled() const {
-    return multi_display_mode_ == MIRRORING;
-  }
-
   void set_change_display_upon_host_resize(bool value) {
     change_display_upon_host_resize_ = value;
   }
@@ -423,7 +437,7 @@ class DISPLAY_MANAGER_EXPORT DisplayManager
   Display* FindDisplayForId(int64_t id);
 
   // Add the mirror display's display info if the software based mirroring is in
-  // use.
+  // use. This should only be called before UpdateDisplaysWith().
   void AddMirrorDisplayInfoIfAny(DisplayInfoList* display_info_list);
 
   // Inserts and update the ManagedDisplayInfo according to the overscan state.
@@ -508,14 +522,25 @@ class DISPLAY_MANAGER_EXPORT DisplayManager
   MultiDisplayMode multi_display_mode_ = EXTENDED;
   MultiDisplayMode current_default_multi_display_mode_ = EXTENDED;
 
-  // When mirroring is enabled this is the id of the destination display.
-  int64_t mirroring_display_id_ = kInvalidDisplayId;
+  // This is used in two distinct ways:
+  // 1. The source display id when software mirroring is active.
+  // 2. There's no source and destination display in hardware mirroring, so we
+  // treat the first mirroring display id as source id when hardware mirroring
+  // is active.
+  int64_t mirroring_source_id_ = kInvalidDisplayId;
 
   // This is used in two distinct ways:
-  // 1. when mirroring is enabled this contains the destination display.
+  // 1. when software mirroring is active this contains the destination
+  // displays.
   // 2. when unified mode is enabled this is the set of physical displays.
   Displays software_mirroring_display_list_;
 
+  // There's no source and destination display in hardware mirroring, so we
+  // treat the first mirroring display as source and store its id in
+  // |mirroring_source_id_| and treat the rest of mirroring displays as
+  // destination and store their ids in this list.
+  DisplayIdList hardware_mirroring_display_id_list_;
+
   // Cached mirror mode for metrics changed notification.
   bool mirror_mode_for_metrics_ = false;