Media Controls: Avoid style recalculation

When generating the media controls DOM we were recalculating
styles each time we called 'AppendChild'. This moves us
to using 'ParserAppendChild' which does not do this.

According to manual testing this reduces the time calculating
styles from 230ms to 139ms.

BUG=821961,821414

Change-Id: I0d673ddc6e12ff81a311315466be735a7673c1bd
Reviewed-on: https://chromium-review.googlesource.com/998187
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548872}

third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp

@@ -155,10 +155,10 @@ bool ShouldShowFullscreenButton(const HTMLMediaElement& media_element) {
   return true;
 }
 
-void MaybeAppendChild(Element* parent, Element* child) {
+void MaybeParserAppendChild(Element* parent, Element* child) {
   DCHECK(parent);
   if (child)
-    parent->AppendChild(child);
+    parent->ParserAppendChild(child);
 }
 
 bool ShouldShowPictureInPictureButton(HTMLMediaElement& media_element) {
@@ -410,7 +410,7 @@ MediaControlsImpl* MediaControlsImpl::Create(HTMLMediaElement& media_element,
 
   MediaControlsResourceLoader::InjectMediaControlsUAStyleSheet();
 
-  shadow_root.AppendChild(controls);
+  shadow_root.ParserAppendChild(controls);
   return controls;
 }
 
@@ -487,7 +487,7 @@ MediaControlsImpl* MediaControlsImpl::Create(HTMLMediaElement& media_element,
 void MediaControlsImpl::InitializeControls() {
   if (IsModern() && MediaElement().IsHTMLVideoElement()) {
     loading_panel_ = new MediaControlLoadingPanelElement(*this);
-    AppendChild(loading_panel_);
+    ParserAppendChild(loading_panel_);
   }
 
   overlay_enclosure_ = new MediaControlOverlayEnclosureElement(*this);
@@ -497,13 +497,13 @@ void MediaControlsImpl::InitializeControls() {
     overlay_play_button_ = new MediaControlOverlayPlayButtonElement(*this);
 
     if (!IsModern())
-      overlay_enclosure_->AppendChild(overlay_play_button_);
+      overlay_enclosure_->ParserAppendChild(overlay_play_button_);
   }
 
   overlay_cast_button_ = new MediaControlCastButtonElement(*this, true);
-  overlay_enclosure_->AppendChild(overlay_cast_button_);
+  overlay_enclosure_->ParserAppendChild(overlay_cast_button_);
 
-  AppendChild(overlay_enclosure_);
+  ParserAppendChild(overlay_enclosure_);
 
   // Create an enclosing element for the panel so we can visually offset the
   // controls correctly.
@@ -549,36 +549,35 @@ void MediaControlsImpl::InitializeControls() {
   overflow_menu_ = new MediaControlOverflowMenuButtonElement(*this);
 
   PopulatePanel();
-  enclosure_->AppendChild(panel_);
+  enclosure_->ParserAppendChild(panel_);
 
-  AppendChild(enclosure_);
+  ParserAppendChild(enclosure_);
 
   text_track_list_ = new MediaControlTextTrackListElement(*this);
-  AppendChild(text_track_list_);
-
+  ParserAppendChild(text_track_list_);
 
   overflow_list_ = new MediaControlOverflowMenuListElement(*this);
-  AppendChild(overflow_list_);
+  ParserAppendChild(overflow_list_);
 
   // The order in which we append elements to the overflow list is significant
   // because it determines how the elements show up in the overflow menu
   // relative to each other.  The first item appended appears at the top of the
   // overflow menu.
-  overflow_list_->AppendChild(play_button_->CreateOverflowElement(
+  overflow_list_->ParserAppendChild(play_button_->CreateOverflowElement(
       new MediaControlPlayButtonElement(*this)));
-  overflow_list_->AppendChild(fullscreen_button_->CreateOverflowElement(
+  overflow_list_->ParserAppendChild(fullscreen_button_->CreateOverflowElement(
       new MediaControlFullscreenButtonElement(*this)));
-  overflow_list_->AppendChild(download_button_->CreateOverflowElement(
+  overflow_list_->ParserAppendChild(download_button_->CreateOverflowElement(
       new MediaControlDownloadButtonElement(*this)));
-  overflow_list_->AppendChild(mute_button_->CreateOverflowElement(
+  overflow_list_->ParserAppendChild(mute_button_->CreateOverflowElement(
       new MediaControlMuteButtonElement(*this)));
-  overflow_list_->AppendChild(cast_button_->CreateOverflowElement(
+  overflow_list_->ParserAppendChild(cast_button_->CreateOverflowElement(
       new MediaControlCastButtonElement(*this, false)));
-  overflow_list_->AppendChild(
+  overflow_list_->ParserAppendChild(
       toggle_closed_captions_button_->CreateOverflowElement(
           new MediaControlToggleClosedCaptionsButtonElement(*this)));
   if (RuntimeEnabledFeatures::PictureInPictureEnabled()) {
-    overflow_list_->AppendChild(
+    overflow_list_->ParserAppendChild(
         picture_in_picture_button_->CreateOverflowElement(
             new MediaControlPictureInPictureButtonElement(*this)));
   }
@@ -596,9 +595,9 @@ void MediaControlsImpl::PopulatePanel() {
   Element* button_panel = panel_;
   if (IsModern() && MediaElement().IsHTMLVideoElement() &&
       !is_acting_as_audio_controls_) {
-    MaybeAppendChild(panel_, scrubbing_message_);
-    panel_->AppendChild(overlay_play_button_);
-    panel_->AppendChild(media_button_panel_);
+    MaybeParserAppendChild(panel_, scrubbing_message_);
+    panel_->ParserAppendChild(overlay_play_button_);
+    panel_->ParserAppendChild(media_button_panel_);
     button_panel = media_button_panel_;
   }
 
@@ -606,35 +605,35 @@ void MediaControlsImpl::PopulatePanel() {
   // only or are using the legacy controls.
   if (!IsModern() || is_acting_as_audio_controls_ ||
       MediaElement().IsHTMLAudioElement()) {
-    button_panel->AppendChild(play_button_);
+    button_panel->ParserAppendChild(play_button_);
   }
 
-  button_panel->AppendChild(current_time_display_);
-  button_panel->AppendChild(duration_display_);
+  button_panel->ParserAppendChild(current_time_display_);
+  button_panel->ParserAppendChild(duration_display_);
 
   if (IsModern() && MediaElement().IsHTMLVideoElement()) {
     MediaControlElementsHelper::CreateDiv(
         "-internal-media-controls-button-spacer", button_panel);
   }
 
-  panel_->AppendChild(timeline_);
+  panel_->ParserAppendChild(timeline_);
 
-  button_panel->AppendChild(mute_button_);
+  button_panel->ParserAppendChild(mute_button_);
 
-  MaybeAppendChild(button_panel, volume_slider_);
-  MaybeAppendChild(button_panel, picture_in_picture_button_);
+  MaybeParserAppendChild(button_panel, volume_slider_);
+  MaybeParserAppendChild(button_panel, picture_in_picture_button_);
 
-  button_panel->AppendChild(fullscreen_button_);
+  button_panel->ParserAppendChild(fullscreen_button_);
 
   // The download, cast and captions buttons should not be present on the modern
   // controls button panel.
   if (!IsModern()) {
-    button_panel->AppendChild(download_button_);
-    button_panel->AppendChild(cast_button_);
-    button_panel->AppendChild(toggle_closed_captions_button_);
+    button_panel->ParserAppendChild(download_button_);
+    button_panel->ParserAppendChild(cast_button_);
+    button_panel->ParserAppendChild(toggle_closed_captions_button_);
   }
 
-  button_panel->AppendChild(overflow_menu_);
+  button_panel->ParserAppendChild(overflow_menu_);
 }
 
 Node::InsertionNotificationRequest MediaControlsImpl::InsertedInto(

third_party/WebKit/Source/modules/media_controls/elements/MediaControlElementsHelper.cpp

@@ -82,7 +82,7 @@ HTMLDivElement* MediaControlElementsHelper::CreateDiv(const AtomicString& id,
   DCHECK(parent);
   HTMLDivElement* element = HTMLDivElement::Create(parent->GetDocument());
   element->SetShadowPseudoId(id);
-  parent->AppendChild(element);
+  parent->ParserAppendChild(element);
   return element;
 }
 
@@ -112,7 +112,7 @@ HTMLDivElement* MediaControlElementsHelper::CreateDivWithId(
   DCHECK(parent);
   HTMLDivElement* element = HTMLDivElement::Create(parent->GetDocument());
   element->setAttribute("id", id);
-  parent->AppendChild(element);
+  parent->ParserAppendChild(element);
   return element;
 }
 

third_party/WebKit/Source/modules/media_controls/elements/MediaControlInputElement.cpp

@@ -66,15 +66,15 @@ HTMLElement* MediaControlInputElement::CreateOverflowElement(
       AtomicString("-internal-media-controls-overflow-menu-list-item"));
   // Appending a button to a label element ensures that clicks on the label
   // are passed down to the button, performing the action we'd expect.
-  element->AppendChild(button);
+  element->ParserAppendChild(button);
 
   if (MediaControlsImpl::IsModern()) {
     overflow_menu_container_ = HTMLDivElement::Create(GetDocument());
-    overflow_menu_container_->AppendChild(overflow_menu_text_);
+    overflow_menu_container_->ParserAppendChild(overflow_menu_text_);
     UpdateOverflowSubtitleElement(button->GetOverflowMenuSubtitleString());
-    element->AppendChild(overflow_menu_container_);
+    element->ParserAppendChild(overflow_menu_container_);
   } else {
-    element->AppendChild(overflow_menu_text_);
+    element->ParserAppendChild(overflow_menu_text_);
   }
 
   // Initialize the internal states of the main element and the overflow one.
@@ -108,7 +108,7 @@ void MediaControlInputElement::UpdateOverflowSubtitleElement(String text) {
     overflow_menu_subtitle_->setInnerText(text, ASSERT_NO_EXCEPTION);
     overflow_menu_subtitle_->setAttribute("class", kOverflowSubtitleCSSClass);
 
-    overflow_menu_container_->AppendChild(overflow_menu_subtitle_);
+    overflow_menu_container_->ParserAppendChild(overflow_menu_subtitle_);
     overflow_menu_container_->setAttribute(
         "class", kOverflowContainerWithSubtitleCSSClass);
   }

third_party/WebKit/Source/modules/media_controls/elements/MediaControlLoadingPanelElement.cpp

@@ -63,7 +63,7 @@ void MediaControlLoadingPanelElement::PopulateShadowDOM() {
   auto* style = HTMLStyleElement::Create(GetDocument(), CreateElementFlags());
   style->setTextContent(
       MediaControlsResourceLoader::GetShadowLoadingStyleSheet());
-  shadow_root->AppendChild(style);
+  shadow_root->ParserAppendChild(style);
 
   // The spinner frame is centers the spinner in the middle of the element and
   // cuts off any overflowing content. It also contains a SVG mask which will

third_party/WebKit/Source/modules/media_controls/elements/MediaControlOverlayPlayButtonElement.cpp

@@ -182,17 +182,18 @@ void MediaControlOverlayPlayButtonElement::MaybeJump(int seconds) {
     auto* style = HTMLStyleElement::Create(GetDocument(), CreateElementFlags());
     style->setTextContent(
         MediaControlsResourceLoader::GetOverlayPlayStyleSheet());
-    shadow_root->AppendChild(style);
+    shadow_root->ParserAppendChild(style);
 
     // Insert the left jump arrow to the left of the play button.
     left_jump_arrow_ = new MediaControlOverlayPlayButtonElement::AnimatedArrow(
         "left-arrow", GetDocument());
-    shadow_root->InsertBefore(left_jump_arrow_, shadow_root->firstChild());
+    shadow_root->ParserInsertBefore(left_jump_arrow_,
+                                    *shadow_root->firstChild());
 
     // Insert the right jump arrow to the right of the play button.
     right_jump_arrow_ = new MediaControlOverlayPlayButtonElement::AnimatedArrow(
         "right-arrow", GetDocument());
-    shadow_root->AppendChild(right_jump_arrow_);
+    shadow_root->ParserAppendChild(right_jump_arrow_);
   }
 
   DCHECK(left_jump_arrow_ && right_jump_arrow_);

third_party/WebKit/Source/modules/media_controls/elements/MediaControlScrubbingMessageElement.cpp

@@ -32,7 +32,7 @@ void MediaControlScrubbingMessageElement::PopulateChildren() {
       HTMLStyleElement::Create(GetDocument(), CreateElementFlags());
   style->setTextContent(
       MediaControlsResourceLoader::GetScrubbingMessageStyleSheet());
-  shadow_root->AppendChild(style);
+  shadow_root->ParserAppendChild(style);
 
   HTMLDivElement* arrow_left_div1 =
       MediaControlElementsHelper::CreateDivWithId("arrow-left1", shadow_root);

third_party/WebKit/Source/modules/media_controls/elements/MediaControlTextTrackListElement.cpp

@@ -120,11 +120,11 @@ Element* MediaControlTextTrackListElement::CreateTextTrackListItem(
   // Modern media controls should have the checkbox after the text instead of
   // the other way around.
   if (!MediaControlsImpl::IsModern())
-    track_item->AppendChild(track_item_input);
+    track_item->ParserAppendChild(track_item_input);
   String track_label = GetMediaControls().GetTextTrackLabel(track);
-  track_item->AppendChild(Text::Create(GetDocument(), track_label));
+  track_item->ParserAppendChild(Text::Create(GetDocument(), track_label));
   if (MediaControlsImpl::IsModern())
-    track_item->AppendChild(track_item_input);
+    track_item->ParserAppendChild(track_item_input);
 
   // Add a track kind marker icon if there are multiple tracks with the same
   // label or if the track has no label.
@@ -138,7 +138,7 @@ Element* MediaControlTextTrackListElement::CreateTextTrackListItem(
       track_kind_marker->SetShadowPseudoId(AtomicString(
           "-internal-media-controls-text-track-list-kind-subtitles"));
     }
-    track_item->AppendChild(track_kind_marker);
+    track_item->ParserAppendChild(track_kind_marker);
   }
   return track_item;
 }
@@ -147,7 +147,7 @@ Element* MediaControlTextTrackListElement::CreateTextTrackHeaderItem() {
   HTMLLabelElement* header_item = HTMLLabelElement::Create(GetDocument());
   header_item->SetShadowPseudoId(
       "-internal-media-controls-text-track-list-header");
-  header_item->AppendChild(
+  header_item->ParserAppendChild(
       Text::Create(GetDocument(),
                    GetLocale().QueryString(
                        WebLocalizedString::kOverflowMenuCaptionsSubmenuTitle)));
@@ -164,18 +164,18 @@ void MediaControlTextTrackListElement::RefreshTextTrackListMenu() {
   RemoveChildren(kOmitSubtreeModifiedEvent);
 
   if (MediaControlsImpl::IsModern())
-    AppendChild(CreateTextTrackHeaderItem());
+    ParserAppendChild(CreateTextTrackHeaderItem());
 
   // Construct a menu for subtitles and captions.  Pass in a nullptr to
   // createTextTrackListItem to create the "Off" track item.
-  AppendChild(CreateTextTrackListItem(nullptr));
+  ParserAppendChild(CreateTextTrackListItem(nullptr));
 
   TextTrackList* track_list = MediaElement().textTracks();
   for (unsigned i = 0; i < track_list->length(); i++) {
     TextTrack* track = track_list->AnonymousIndexedGetter(i);
     if (!track->CanBeRendered())
       continue;
-    AppendChild(CreateTextTrackListItem(track));
+    ParserAppendChild(CreateTextTrackListItem(track));
   }
 }
 

third_party/WebKit/Source/modules/media_controls/elements/MediaControlTimelineElement.cpp

@@ -77,7 +77,7 @@ MediaControlTimelineElement::MediaControlTimelineElement(
     auto* style = HTMLStyleElement::Create(GetDocument(), CreateElementFlags());
     style->setTextContent(
         MediaControlsResourceLoader::GetShadowTimelineStyleSheet());
-    track.AppendChild(style);
+    track.ParserAppendChild(style);
   }
 }