Change CaptureSynchronizer and PointerWatcherEventRouter to support multiple CaptureClients.

ui/aura/mus/window_tree_client_unittest.cc

Index: ui/aura/mus/window_tree_client_unittest.cc
diff --git a/ui/aura/mus/window_tree_client_unittest.cc b/ui/aura/mus/window_tree_client_unittest.cc
index 66fa7d876a5090371f8692f73da577a300b277d5..ae0c84c5d7ca026b0da5bf04b2975746d69f2399 100644
--- a/ui/aura/mus/window_tree_client_unittest.cc
+++ b/ui/aura/mus/window_tree_client_unittest.cc
@@ -18,6 +18,7 @@
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/client/capture_client_observer.h"
+#include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/client/transient_window_client.h"
 #include "ui/aura/mus/property_converter.h"
@@ -1364,6 +1365,66 @@ TEST_F(WindowTreeClientWmTest, OnWindowTreeCaptureChanged) {
   capture_recorder.reset_capture_captured_count();
 }
 
+TEST_F(WindowTreeClientClientTest, TwoWindowTreesRequestCapture) {
+  // Creating a WindowTreeHost so we can have two root windows: top_level
+  // and root_window().
+  WindowTreeHostMus window_tree_host(window_tree_client_impl());
+  Window* top_level = window_tree_host.window();
+  window_tree_host.InitHost();
+  client::DefaultCaptureClient capture_client;
+  client::SetCaptureClient(top_level, &capture_client);
+  EXPECT_NE(server_id(top_level), server_id(root_window()));
+
+  // Ack the request to the windowtree to create the new window.
+  uint32_t change_id;
+  ASSERT_TRUE(window_tree()->GetAndRemoveFirstChangeOfType(
+      WindowTreeChangeType::NEW_TOP_LEVEL, &change_id));
+  EXPECT_EQ(window_tree()->window_id(), server_id(top_level));
+
+  ui::mojom::WindowDataPtr data = ui::mojom::WindowData::New();
+  data->window_id = server_id(top_level);
+  data->visible = true;
+  const int64_t display_id = 1;
+  window_tree_client()->OnTopLevelCreated(change_id, std::move(data),
+                                          display_id, true);
+  EXPECT_EQ(
+      0u, window_tree()->GetChangeCountForType(WindowTreeChangeType::VISIBLE));
+  EXPECT_TRUE(top_level->TargetVisibility());
+
+  CaptureRecorder capture_recorder1(root_window());
+  CaptureRecorder capture_recorder2(top_level);
+  EXPECT_NE(client::GetCaptureClient(root_window()),
+            client::GetCaptureClient(top_level));
+
+  EXPECT_EQ(0, capture_recorder1.capture_changed_count());
+  EXPECT_EQ(0, capture_recorder2.capture_changed_count());
+  // Give capture to top_level and ensure everyone is notified correctly.
+  top_level->SetCapture();
+  ASSERT_TRUE(window_tree()->AckSingleChangeOfType(
+      WindowTreeChangeType::CAPTURE, true));
+  EXPECT_EQ(0, capture_recorder1.capture_changed_count());
+  EXPECT_EQ(1, capture_recorder2.capture_changed_count());
+  EXPECT_EQ(top_level->id(), capture_recorder2.last_gained_capture_window_id());
+  EXPECT_EQ(0, capture_recorder2.last_lost_capture_window_id());
+  top_level->ReleaseCapture();
+  capture_recorder1.reset_capture_captured_count();
+  capture_recorder2.reset_capture_captured_count();
+
+  // Release capture of top_level shouldn't affect the capture of root_window().
+  top_level->SetCapture();
+  root_window()->SetCapture();
+  top_level->ReleaseCapture();
+  EXPECT_EQ(1, capture_recorder1.capture_changed_count());
+  EXPECT_EQ(2, capture_recorder2.capture_changed_count());
+  EXPECT_EQ(root_window()->id(),
+            capture_recorder1.last_gained_capture_window_id());
+  EXPECT_EQ(0, capture_recorder1.last_lost_capture_window_id());
+  EXPECT_EQ(0, capture_recorder2.last_gained_capture_window_id());
+  EXPECT_EQ(top_level->id(), capture_recorder2.last_lost_capture_window_id());
+  capture_recorder1.reset_capture_captured_count();
+  capture_recorder2.reset_capture_captured_count();
+}
+
 TEST_F(WindowTreeClientClientTest, ModalFail) {
   Window window(nullptr);
   window.Init(ui::LAYER_NOT_DRAWN);