Reland "exo: Allow Pointer Capture when window is active"

This reverts commit b89a947a.

Reason for revert: The CTS failures caused by landing this change
for P are being addressed in ag/13257099. For changes required for R,
see b/176433665.

Original change's description:
> Revert "exo: Allow Pointer Capture when window is active"
>
> This reverts commit 43be36f0.
>
> Reason for revert: Multiple CTS failures
>
> Bug: b:175379280
> Bug: b:175514308
> Bug: b:175829322
>
> Original change's description:
> > exo: Allow Pointer Capture when window is active
> >
> > Pointer Capture was being rejected by chrome when an app came into
> > focus using keyboard shortcuts (Alt-Tab), but was working as intended
> > when an app came into focus using the mouse or touchscreen. It was being
> > rejected because the capture_surface was the sub-surface of the current
> > focused surface.
> >
> > Since the client is responsible for providing the capture surface
> > through the wayland pointer constraints protocol, it is possible
> > for the client to request capture on a sub-surface of the current
> > active surface. Requesting capture on a sub-surface is a valid request
> > for capture. Rather than ensuring that the capture surface is focused
> > (used for directing key events), we verify that the active window
> > contains the window of the capture surface in its hierarchy before we
> > allow the pointer to be constrained to the surface.
> >
> > This also allows the client to change the cursor while the client has
> > capture, even when the mouse cursor is not currently over a client
> > window.
> >
> > BUG=b:153973515
> > TEST=manual: request pointer capture, leave app, return to app using
> > Alt+Tab, verify app has pointer capture.
> > TEST=exo_unittests
> >
> > Change-Id: I56e76469f35ea43100748ebe27966464e32805fc
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2559255
> > Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
> > Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
> > Commit-Queue: Prabir Pradhan <prabirmsp@chromium.org>
> > Auto-Submit: Prabir Pradhan <prabirmsp@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#832613}
>
> TBR=oshima@chromium.org,tetsui@chromium.org,prabirmsp@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com
>
> # Not skipping CQ checks because original CL landed > 1 day ago.
>
> Bug: b:153973515
> Change-Id: I582f775f37c34149fb7f0c2a6b9162b5e72cbf78
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2596065
> Commit-Queue: Prabir Pradhan <prabirmsp@chromium.org>
> Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
> Auto-Submit: Prabir Pradhan <prabirmsp@chromium.org>
> Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#837908}

TBR=oshima@chromium.org,tetsui@chromium.org,prabirmsp@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: b:175379280
Bug: b:175514308
Bug: b:175829322
Bug: b:153973515
Change-Id: I967663e2936a7d117ee2dce9edb8967ce922dd91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2605465Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Commit-Queue: Prabir Pradhan <prabirmsp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843233}

components/exo/pointer.cc

@@ -155,8 +155,7 @@ Pointer::~Pointer() {
 }
 
 void Pointer::SetCursor(Surface* surface, const gfx::Point& hotspot) {
-  // Early out if the pointer doesn't have a surface in focus.
-  if (!focus_surface_)
+  if (!focus_surface_ && !capture_window_)
     return;
 
   // This is used to avoid unnecessary cursor changes.
@@ -242,6 +241,8 @@ bool Pointer::ConstrainPointer(PointerConstraintDelegate* delegate) {
   // lock support unless we are on chromeos.
 #if BUILDFLAG(IS_CHROMEOS_ASH)
   Surface* constrained_surface = delegate->GetConstrainedSurface();
+  if (!constrained_surface)
+    return false;
   // Pointer lock should be enabled for ARC by default. The kExoPointerLock
   // should only apply to Crostini windows.
   bool is_arc_window =
@@ -272,17 +273,17 @@ bool Pointer::EnablePointerCapture(Surface* capture_surface) {
     return false;
   }
 
-  if (capture_surface->window() !=
-      WMHelper::GetInstance()->GetFocusedWindow()) {
-    LOG(ERROR)
-        << "Cannot enable pointer capture on a window that is not focused.";
+  aura::Window* window = capture_surface->window();
+  aura::Window* active_window = WMHelper::GetInstance()->GetActiveWindow();
+  if (!active_window || !active_window->Contains(window)) {
+    LOG(ERROR) << "Cannot enable pointer capture on an inactive window.";
     return false;
   }
 
   if (!capture_surface->HasSurfaceObserver(this))
     capture_surface->AddSurfaceObserver(this);
 
-  capture_window_ = capture_surface->window();
+  capture_window_ = window;
 
   // Add a pre-target handler that can consume all mouse events before it gets
   // sent to other targets.

components/exo/pointer_unittest.cc

@@ -1200,7 +1200,7 @@ TEST_F(PointerTest, ConstrainPointer) {
 #endif
 
 #if BUILDFLAG(IS_CHROMEOS_ASH)
-TEST_F(PointerTest, ConstrainPointerFailsWhenSurfaceIsNotFocused) {
+TEST_F(PointerTest, ConstrainPointerFailsWhenSurfaceIsNotActive) {
   auto scoped_feature_list = std::make_unique<base::test::ScopedFeatureList>();
   scoped_feature_list->InitAndEnableFeature(
       chromeos::features::kExoPointerLock);
@@ -1219,7 +1219,6 @@ TEST_F(PointerTest, ConstrainPointerFailsWhenSurfaceIsNotFocused) {
   auto pointer = std::make_unique<Pointer>(&delegate, &seat);
   aura::client::FocusClient* focus_client =
       aura::client::GetFocusClient(ash::Shell::GetPrimaryRootWindow());
-  focus_client->FocusWindow(nullptr);
   ui::test::EventGenerator generator(ash::Shell::GetPrimaryRootWindow());
 
   EXPECT_CALL(delegate, CanAcceptPointerEventsForSurface(surface.get()))
@@ -1227,24 +1226,20 @@ TEST_F(PointerTest, ConstrainPointerFailsWhenSurfaceIsNotFocused) {
 
   EXPECT_CALL(constraint_delegate, GetConstrainedSurface())
       .WillRepeatedly(testing::Return(surface.get()));
-  EXPECT_FALSE(pointer->ConstrainPointer(&constraint_delegate));
 
-  auto child_surface = std::make_unique<Surface>();
-  auto child_shell_surface = std::make_unique<ShellSurface>(
-      child_surface.get(), gfx::Point(), true, false,
-      ash::desks_util::GetActiveDeskContainerId());
-  child_shell_surface->DisableMovement();
-  child_shell_surface->SetParent(shell_surface.get());
-  gfx::Size child_buffer_size(15, 15);
-  auto child_buffer = std::make_unique<Buffer>(
-      exo_test_helper()->CreateGpuMemoryBuffer(child_buffer_size));
-  child_surface->Attach(child_buffer.get());
-  child_surface->Commit();
+  auto second_surface = std::make_unique<Surface>();
+  auto second_shell_surface =
+      std::make_unique<ShellSurface>(second_surface.get());
+  auto second_buffer = std::make_unique<Buffer>(
+      exo_test_helper()->CreateGpuMemoryBuffer(buffer_size));
+  second_surface->Attach(second_buffer.get());
+  second_surface->Commit();
 
-  EXPECT_CALL(delegate, CanAcceptPointerEventsForSurface(child_surface.get()))
+  EXPECT_CALL(delegate, CanAcceptPointerEventsForSurface(second_surface.get()))
       .WillRepeatedly(testing::Return(true));
 
-  focus_client->FocusWindow(child_surface->window());
+  // Setting the focused window also makes it activated.
+  focus_client->FocusWindow(second_surface->window());
   EXPECT_FALSE(pointer->ConstrainPointer(&constraint_delegate));
 
   focus_client->FocusWindow(surface->window());