[Picture in Picture] Activate controls using enter / space keys.

This change adds in KeyEvent handling to support keyboard usage with
the controls buttons. They should be activated when the 'enter' or
'space' keys are used.

The previous implementation of OnKeyEvent used an OverlayWindowViews
tracking of which control is being focused, which is now obsolete.

Bug: 866291
Change-Id: I8a59337aa7aef5c95da081a9b5f33762462eeaef
Reviewed-on: https://chromium-review.googlesource.com/1146283Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577172}

chrome/browser/ui/views/overlay/overlay_window_views.cc

@@ -493,6 +493,22 @@ void OverlayWindowViews::OnNativeWidgetWorkspaceChanged() {
   // does not trigger this function. http://crbug.com/819673
 }
 
+void OverlayWindowViews::OnKeyEvent(ui::KeyEvent* event) {
+  if (event->type() != ui::ET_KEY_RELEASED)
+    return;
+
+  if (event->key_code() == ui::VKEY_RETURN ||
+      event->key_code() == ui::VKEY_SPACE) {
+    if (play_pause_controls_view_->HasFocus()) {
+      TogglePlayPause();
+    } else if (close_controls_view_->HasFocus()) {
+      controller_->Close(true /* should_pause_video */);
+    }
+
+    event->SetHandled();
+  }
+}
+
 void OverlayWindowViews::OnMouseEvent(ui::MouseEvent* event) {
   switch (event->type()) {
     // Only show the media controls when the mouse is hovering over the window.

chrome/browser/ui/views/overlay/overlay_window_views.h

@@ -42,6 +42,7 @@ class OverlayWindowViews : public content::OverlayWindow, public views::Widget {
   gfx::Size GetMinimumSize() const override;
   gfx::Size GetMaximumSize() const override;
   void OnNativeWidgetWorkspaceChanged() override;
+  void OnKeyEvent(ui::KeyEvent* event) override;
   void OnMouseEvent(ui::MouseEvent* event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;