Add two names to shadow_element_names.json5

This CL adds "-internal-media-controls-segmented-track" and
"-webkit-slider-runnable-track" to shadow_element_names.json5.

This CL has no behavior changes, and is a preparation to port
LayoutSliderTrack to LayoutNG.

Bug: 1040826
Change-Id: I6558e1221dc748091b2972fc6e5e7452346206df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2418271
Auto-Submit: Kent Tamura <tkent@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808457}

third_party/blink/renderer/core/html/forms/range_input_type.cc

@@ -246,7 +246,7 @@ void RangeInputType::CreateShadowSubtree() {
 
   Document& document = GetElement().GetDocument();
   auto* track = MakeGarbageCollected<blink::SliderTrackElement>(document);
-  track->SetShadowPseudoId(AtomicString("-webkit-slider-runnable-track"));
+  track->SetShadowPseudoId(shadow_element_names::kPseudoSliderTrack);
   track->setAttribute(html_names::kIdAttr,
                       shadow_element_names::kIdSliderTrack);
   track->AppendChild(MakeGarbageCollected<SliderThumbElement>(document));

third_party/blink/renderer/core/html/shadow/shadow_element_names.json5

@@ -93,6 +93,10 @@
       name: "-internal-input-suggested",
       Symbol: "kPseudoInternalInputSuggested",
     },
+    {
+      name: "-internal-media-controls-segmented-track",
+      Symbol: "kPseudoMediaControlsSegmentedTrack",
+    },
     {
       name: "-webkit-media-slider-container",
       Symbol: "kPseudoMediaSliderContainer",
@@ -105,6 +109,10 @@
       name: "-webkit-slider-container",
       Symbol: "kPseudoSliderContainer",
     },
+    {
+      name: "-webkit-slider-runnable-track",
+      Symbol: "kPseudoSliderTrack",
+    },
     {
       name: "-webkit-textfield-decoration-container",
       Symbol: "kPseudoTextFieldDecorationContainer",

third_party/blink/renderer/modules/media_controls/elements/media_control_slider_element.cc

@@ -5,6 +5,7 @@
 #include "third_party/blink/renderer/modules/media_controls/elements/media_control_slider_element.h"
 
 #include "third_party/blink/renderer/core/html/html_div_element.h"
+#include "third_party/blink/renderer/core/html/shadow/shadow_element_names.h"
 #include "third_party/blink/renderer/core/input_type_names.h"
 #include "third_party/blink/renderer/core/layout/layout_box.h"
 #include "third_party/blink/renderer/core/layout/layout_box_model_object.h"
@@ -114,7 +115,8 @@ void MediaControlSliderElement::SetupBarSegments() {
     return;
 
   Element& track = GetTrackElement();
-  track.SetShadowPseudoId("-internal-media-controls-segmented-track");
+  track.SetShadowPseudoId(
+      shadow_element_names::kPseudoMediaControlsSegmentedTrack);
 
   // Add the following structure to #track.
   //