Add html/details_summary to virtual/incremental-shadow-dom test suites

I am preparing to make IncrementalShadowDOM runtime flag an experimental flag,
however, some tests in html_details are still failing when the flag is enabled.

To track and fix these surely, add these tests to virtual/incremental-shadow-dom test
suites.

Bug: 776656
Change-Id: Ied9d5ff914fc998a04efac1d944708c313e82b7b
Reviewed-on: https://chromium-review.googlesource.com/914944Reviewed-by: Takayoshi Kochi <kochi@chromium.org>
Commit-Queue: Hayato Ito <hayato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#536599}

third_party/WebKit/LayoutTests/TestExpectations

@@ -529,6 +529,30 @@ crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/position-re
 
 crbug.com/776656 virtual/incremental-shadow-dom/external/wpt/shadow-dom/untriaged/styles/test-003.html [ Failure ]
 
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-1-and-click.html [ Crash ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-1.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-10-and-click.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-10.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-2-and-click.html [ Crash ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-2.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-3-and-click.html [ Crash ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-3.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-5.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-6-and-click.html [ Crash ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-6.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-7-and-click.html [ Crash ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-7.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-8-and-click.html [ Crash ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-add-summary-8.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-1-and-click.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-1.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-2-and-click.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-2.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-4-and-click.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-4.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-5-and-click.html [ Failure ]
+crbug.com/776656 virtual/incremental-shadow-dom/html/details_summary/details-remove-summary-5.html [ Failure ]
+
 # ====== IncrementalShadowDOM-only failures until here ======
 
 crbug.com/667560 [ Debug ] http/tests/devtools/elements/styles-3/styles-change-node-while-editing.js [ Pass Failure ]

third_party/WebKit/LayoutTests/VirtualTestSuites

@@ -574,6 +574,11 @@
     "base": "shadow-dom",
     "args": ["--enable-blink-features=SlotInFlatTree,IncrementalShadowDOM"]
   },
+  {
+    "prefix": "incremental-shadow-dom",
+    "base": "html/details_summary",
+    "args": ["--enable-blink-features=SlotInFlatTree,IncrementalShadowDOM"]
+  },
   {
     "prefix": "incremental-shadow-dom",
     "base": "external/wpt/css/css-scoping",

third_party/WebKit/LayoutTests/virtual/incremental-shadow-dom/html/details_summary/README.txt

+# This suite runs the tests in html/details_summary with
+# --enable-blink-features=IncrementalShadowDOM.
+# See crbug.com/776656 for details.