Let PIP windows be resized in tablet mode as well.

free resize it.

Bug: b/113151342
Test: unit test + opened a PIP window in tablet mode and was able to
Change-Id: Ic72478a35c5726e7ffa2e89fd61243b87f4bf4d7
Reviewed-on: https://chromium-review.googlesource.com/1188404Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Eliot Courtney <edcourtney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585876}

ash/wm/workspace/workspace_window_resizer.cc

@@ -65,7 +65,8 @@ std::unique_ptr<WindowResizer> CreateWindowResizer(
 
   if (Shell::Get()
           ->tablet_mode_controller()
-          ->IsTabletModeWindowManagerEnabled()) {
+          ->IsTabletModeWindowManagerEnabled() &&
+      !window_state->IsPip()) {
     // We still don't allow any dragging or resizing happening on the area other
     // then caption area.
     if (window_component != HTCAPTION)

ash/wm/workspace/workspace_window_resizer_unittest.cc

@@ -11,6 +11,7 @@
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/window_factory.h"
+#include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "ash/wm/window_positioning_utils.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
@@ -1903,4 +1904,28 @@ TEST_F(WorkspaceWindowResizerTest, PipCanBeResized) {
   EXPECT_EQ("20,30 100x60", fake_state->last_bounds().ToString());
 }
 
+TEST_F(WorkspaceWindowResizerTest, PipCanBeResizedInTabletMode) {
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+
+  aura::Window* root_window = Shell::GetPrimaryRootWindow();
+  aura::Window* container =
+      Shell::GetContainer(root_window, kShellWindowId_AlwaysOnTopContainer);
+  std::unique_ptr<aura::Window> window(
+      aura::test::CreateTestWindowWithId(0, container));
+  window->SetBounds(gfx::Rect(20, 30, 50, 60));
+  window->Show();
+
+  auto* fake_state = new FakeWindowState(mojom::WindowStateType::PIP);
+  wm::WindowState* window_state = wm::GetWindowState(window.get());
+  window_state->SetStateObject(
+      std::unique_ptr<wm::WindowState::State>(fake_state));
+
+  std::unique_ptr<WindowResizer> resizer(
+      CreateResizerForTest(window.get(), gfx::Point(), HTRIGHT));
+  ASSERT_TRUE(resizer.get());
+  resizer->Drag(CalculateDragPoint(*resizer, 50, 0), 0);
+  resizer->CompleteDrag();
+  EXPECT_EQ("20,30 100x60", fake_state->last_bounds().ToString());
+}
+
 }  // namespace ash