EXO: Add OnDisplayMetricsChanged, TargetHandlers for WMHelperCastShell

Change OnDisplayMetricsChanged to create new ManagedDisplayInfo for
display if OnDisplayAdded was never called for the display.
This is needed for the initial display on cast.

Bug: 896710
Test: None
Change-Id: I3b7d4829874b61b2115d25071a0de7bb74dba246
Reviewed-on: https://chromium-review.googlesource.com/c/1329859
Commit-Queue: Daniel Nicoara <dnicoara@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611692}

chromecast/browser/exo/wm_helper_cast_shell.cc

@@ -131,7 +131,7 @@ aura::client::CursorClient* WMHelperCastShell::GetCursorClient() {
 }
 
 void WMHelperCastShell::AddPreTargetHandler(ui::EventHandler* handler) {
-  NOTIMPLEMENTED();
+  cast_window_manager_aura_->GetRootWindow()->AddPreTargetHandler(handler);
 }
 
 void WMHelperCastShell::PrependPreTargetHandler(ui::EventHandler* handler) {
@@ -139,15 +139,15 @@ void WMHelperCastShell::PrependPreTargetHandler(ui::EventHandler* handler) {
 }
 
 void WMHelperCastShell::RemovePreTargetHandler(ui::EventHandler* handler) {
-  NOTIMPLEMENTED();
+  cast_window_manager_aura_->GetRootWindow()->RemovePreTargetHandler(handler);
 }
 
 void WMHelperCastShell::AddPostTargetHandler(ui::EventHandler* handler) {
-  NOTIMPLEMENTED();
+  cast_window_manager_aura_->GetRootWindow()->AddPostTargetHandler(handler);
 }
 
 void WMHelperCastShell::RemovePostTargetHandler(ui::EventHandler* handler) {
-  NOTIMPLEMENTED();
+  cast_window_manager_aura_->GetRootWindow()->RemovePostTargetHandler(handler);
 }
 
 bool WMHelperCastShell::IsTabletModeWindowManagerEnabled() const {
@@ -183,6 +183,12 @@ void WMHelperCastShell::CastDisplayObserver::OnDisplayRemoved(
 void WMHelperCastShell::CastDisplayObserver::OnDisplayMetricsChanged(
     const display::Display& display,
     uint32_t changed_metrics) {
+  if (!base::ContainsValue(display_info_, display.id())) {
+    display::ManagedDisplayInfo md(display.id(), "CastDisplayInfo", true);
+    md.SetBounds(display.bounds());
+    display_info_.emplace(display.id(), md);
+  }
+
   // Currently only updates bounds
   if ((DISPLAY_METRIC_BOUNDS & changed_metrics) == DISPLAY_METRIC_BOUNDS)
     display_info_[display.id()].SetBounds(display.bounds());