Prevent maximize/minimize/fullscreen-ize window in trusted pinned mode.

If the window is in the trusted pinned mode,
we do not expect that can enter into another mode, e.g.
maximized/minimized/fulscreen mode, without explicit
unpin action by client.

BUG=665943
TEST=Ran trybots. Tested in ARC kiosk mode, and the apps can continue
     to run on a pinnded window.

Review-Url: https://codereview.chromium.org/2590123002
Cr-Commit-Position: refs/heads/master@{#441872}

ash/common/wm/default_state.cc

@@ -167,6 +167,10 @@ void DefaultState::OnWMEvent(WindowState* window_state, const WMEvent* event) {
   if (ProcessWorkspaceEvents(window_state, event))
     return;
 
+  // Do not change the PINNED window state if this is not unpin event.
+  if (window_state->IsTrustedPinned() && event->type() != WM_EVENT_NORMAL)
+    return;
+
   if (ProcessCompoundEvents(window_state, event))
     return;
 

ash/common/wm/window_state.cc

@@ -87,6 +87,10 @@ bool WindowState::IsPinned() const {
          GetStateType() == WINDOW_STATE_TYPE_TRUSTED_PINNED;
 }
 
+bool WindowState::IsTrustedPinned() const {
+  return GetStateType() == WINDOW_STATE_TYPE_TRUSTED_PINNED;
+}
+
 bool WindowState::IsNormalStateType() const {
   return GetStateType() == WINDOW_STATE_TYPE_NORMAL ||
          GetStateType() == WINDOW_STATE_TYPE_DEFAULT;

ash/common/wm/window_state.h

@@ -97,6 +97,7 @@ class ASH_EXPORT WindowState {
   bool IsFullscreen() const;
   bool IsSnapped() const;
   bool IsPinned() const;
+  bool IsTrustedPinned() const;
 
   // True if the window's state type is WINDOW_STATE_TYPE_MAXIMIZED,
   // WINDOW_STATE_TYPE_FULLSCREEN or WINDOW_STATE_TYPE_PINNED.

ash/wm/window_state_unittest.cc

@@ -11,6 +11,7 @@
 #include "ash/common/wm/wm_event.h"
 #include "ash/test/ash_md_test_base.h"
 #include "ash/wm/window_state_aura.h"
+#include "ash/wm/window_util.h"
 #include "services/ui/public/interfaces/window_manager_constants.mojom.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/test/test_window_delegate.h"
@@ -360,6 +361,33 @@ TEST_P(WindowStateTest, DoNotResizeMaximizedWindowInFullscreen) {
             maximized->GetBoundsInScreen().ToString());
 }
 
+TEST_P(WindowStateTest, TrustedPinned) {
+  std::unique_ptr<aura::Window> window(CreateTestWindowInShellWithId(0));
+  WindowState* window_state = GetWindowState(window.get());
+  EXPECT_FALSE(window_state->IsTrustedPinned());
+  wm::PinWindow(window.get(), true /* trusted */);
+  EXPECT_TRUE(window_state->IsTrustedPinned());
+
+  gfx::Rect work_area =
+      display::Screen::GetScreen()->GetPrimaryDisplay().work_area();
+  EXPECT_EQ(work_area.ToString(), window->bounds().ToString());
+
+  // Sending non-unpin/non-workspace related event should be ignored.
+  {
+    const WMEvent fullscreen_event(WM_EVENT_FULLSCREEN);
+    window_state->OnWMEvent(&fullscreen_event);
+  }
+  EXPECT_TRUE(window_state->IsTrustedPinned());
+
+  // Update display triggers workspace event.
+  UpdateDisplay("300x200");
+  EXPECT_EQ("0,0 300x200", window->GetBoundsInScreen().ToString());
+
+  // Unpin should work.
+  window_state->Restore();
+  EXPECT_FALSE(window_state->IsTrustedPinned());
+}
+
 TEST_P(WindowStateTest, AllowSetBoundsInMaximized) {
   std::unique_ptr<aura::Window> window(CreateTestWindowInShellWithId(0));
   WindowState* window_state = GetWindowState(window.get());