window-service: don't do a grab when in unified mode

Classic ash doesn't do grabs when in unified mode. For compatibility
this patch makes the window-service not execute a grab when in unified
mode. To execute a grab leads to ash doing the wrong event conversion.

BUG=804460,773348
TEST=covered by test

Change-Id: I6d402ec4eb5d68946f98757cc4a56e850bd1e8b0
Reviewed-on: https://chromium-review.googlesource.com/884569
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531828}

services/ui/ws/display_manager.cc

@@ -304,7 +304,7 @@ const Display* DisplayManager::GetDisplayContaining(
   return nullptr;
 }
 
-Display* DisplayManager::GetDisplayById(int64_t display_id) {
+const Display* DisplayManager::GetDisplayById(int64_t display_id) const {
   for (Display* display : displays_) {
     if (display->GetId() == display_id)
       return display;
@@ -333,6 +333,10 @@ WindowManagerDisplayRoot* DisplayManager::GetWindowManagerDisplayRoot(
           window));
 }
 
+bool DisplayManager::InUnifiedDisplayMode() const {
+  return GetDisplayById(display::kUnifiedDisplayId) != nullptr;
+}
+
 WindowId DisplayManager::GetAndAdvanceNextRootId() {
   // TODO(sky): handle wrapping!
   const uint16_t id = next_root_id_++;

services/ui/ws/display_manager.h

@@ -89,7 +89,11 @@ class DisplayManager : public UserIdTrackerObserver,
 
   // Returns the display with the specified display id, or null if there is no
   // display with that id.
-  Display* GetDisplayById(int64_t display_id);
+  const Display* GetDisplayById(int64_t display_id) const;
+  Display* GetDisplayById(int64_t display_id) {
+    return const_cast<Display*>(
+        const_cast<const DisplayManager*>(this)->GetDisplayById(display_id));
+  }
 
   const WindowManagerDisplayRoot* GetWindowManagerDisplayRoot(
       const ServerWindow* window) const;
@@ -104,6 +108,8 @@ class DisplayManager : public UserIdTrackerObserver,
     return !displays_.empty() || !pending_displays_.empty();
   }
 
+  bool InUnifiedDisplayMode() const;
+
   // Returns the id for the next root window (both for the root of a Display
   // as well as the root of WindowManagers).
   WindowId GetAndAdvanceNextRootId();

services/ui/ws/test_utils.cc

@@ -727,8 +727,12 @@ void TestPlatformDisplay::Init(PlatformDisplayDelegate* delegate) {
 }
 void TestPlatformDisplay::SetViewportSize(const gfx::Size& size) {}
 void TestPlatformDisplay::SetTitle(const base::string16& title) {}
-void TestPlatformDisplay::SetCapture() {}
-void TestPlatformDisplay::ReleaseCapture() {}
+void TestPlatformDisplay::SetCapture() {
+  has_capture_ = true;
+}
+void TestPlatformDisplay::ReleaseCapture() {
+  has_capture_ = false;
+}
 void TestPlatformDisplay::SetCursor(const ui::CursorData& cursor) {
   *cursor_storage_ = cursor;
 }

services/ui/ws/test_utils.h

@@ -809,6 +809,8 @@ class TestPlatformDisplay : public PlatformDisplay {
 
   const display::ViewportMetrics& metrics() const { return metrics_; }
 
+  bool has_capture() const { return has_capture_; }
+
   // PlatformDisplay:
   void Init(PlatformDisplayDelegate* delegate) override;
   void SetViewportSize(const gfx::Size& size) override;
@@ -836,6 +838,7 @@ class TestPlatformDisplay : public PlatformDisplay {
       display::Display::Rotation::ROTATE_0;
   float cursor_scale_ = 1.0f;
   gfx::Rect confine_cursor_bounds_;
+  bool has_capture_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(TestPlatformDisplay);
 };

services/ui/ws/window_manager_state.cc

@@ -730,6 +730,12 @@ ServerWindow* WindowManagerState::GetFocusedWindowForEventDispatcher(
 void WindowManagerState::SetNativeCapture(ServerWindow* window) {
   DCHECK(window);
   DCHECK(IsActive());
+
+  // Classic ash expects no native grab when in unified display.
+  // See http://crbug.com/773348 for details.
+  if (display_manager()->InUnifiedDisplayMode())
+    return;
+
   WindowManagerDisplayRoot* display_root =
       display_manager()->GetWindowManagerDisplayRoot(window);
   DCHECK(display_root);
@@ -738,6 +744,11 @@ void WindowManagerState::SetNativeCapture(ServerWindow* window) {
 }
 
 void WindowManagerState::ReleaseNativeCapture() {
+  // Classic ash expects no native grab when in unified display.
+  // See http://crbug.com/773348 for details.
+  if (display_manager()->InUnifiedDisplayMode())
+    return;
+
   // Tests trigger calling this without a corresponding SetNativeCapture().
   // TODO(sky): maybe abstract this away so that DCHECK can be added?
   if (!platform_display_with_capture_)

services/ui/ws/window_manager_state_unittest.cc

@@ -839,6 +839,27 @@ TEST_F(WindowManagerStateTest, CursorLocationManagerUpdatedOnMouseMove) {
                           .current_cursor_location()));
 }
 
+TEST_F(WindowManagerStateTest, SetCapture) {
+  ASSERT_EQ(1u, window_server()->display_manager()->displays().size());
+  Display* display = *(window_server()->display_manager()->displays().begin());
+  TestPlatformDisplay* platform_display =
+      static_cast<TestPlatformDisplay*>(display->platform_display());
+  EXPECT_TRUE(window_tree()->SetCapture(FirstRootId(window_tree())));
+  EXPECT_EQ(FirstRoot(window_tree()), window_manager_state()->capture_window());
+  EXPECT_TRUE(platform_display->has_capture());
+  EXPECT_TRUE(window_tree()->ReleaseCapture(FirstRootId(window_tree())));
+  EXPECT_FALSE(platform_display->has_capture());
+
+  // In unified mode capture should not propagate to the PlatformDisplay. This
+  // is for compatibility with classic ash. See http://crbug.com/773348.
+  display->SetDisplay(display::Display(display::kUnifiedDisplayId));
+  EXPECT_TRUE(window_tree()->SetCapture(FirstRootId(window_tree())));
+  EXPECT_EQ(FirstRoot(window_tree()), window_manager_state()->capture_window());
+  EXPECT_FALSE(platform_display->has_capture());
+  EXPECT_TRUE(window_tree()->ReleaseCapture(FirstRootId(window_tree())));
+  EXPECT_FALSE(platform_display->has_capture());
+}
+
 TEST_F(WindowManagerStateTestAsync, CursorResetOverNoTargetAsync) {
   ASSERT_EQ(1u, window_server()->display_manager()->displays().size());
   const ClientWindowId child_window_id(window_tree()->id(), 11);