RuleSet invalidations on single feature only, including tags.

third_party/WebKit/Source/core/dom/StyleEngineTest.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/StyleEngine.h"
 
 #include "core/css/StyleSheetContents.h"
 #include "core/css/parser/CSSParserContext.h"
 #include "core/dom/Document.h"
 #include "core/dom/NodeComputedStyle.h"
@@ skipping 123 matching lines @@
   // Check that we did not use a cached StyleSheetContents after the garbage
   // collection.
   EXPECT_FALSE(sheet1->contents()->isUsedFromTextCache());
 }
 
 TEST_F(StyleEngineTest, RuleSetInvalidationTypeSelectors) {
   document().body()->setInnerHTML(
       "<div>"
       "  <span></span>"
       "  <div></div>"
-      "</div>");
+      "</div>"
+      "<b></b><b></b><b></b><b></b>"
+      "<i id=i>"
+      "  <i>"
+      "    <b></b>"
+      "  </i>"
+      "</i>");
 
   document().view()->updateAllLifecyclePhases();
 
   unsigned beforeCount = styleEngine().styleForElementCount();
   EXPECT_EQ(
       scheduleInvalidationsForRules(document(), "span { background: green}"),
       RuleSetInvalidationsScheduled);
   document().view()->updateAllLifecyclePhases();
   unsigned afterCount = styleEngine().styleForElementCount();
   EXPECT_EQ(1u, afterCount - beforeCount);
 
   beforeCount = afterCount;
   EXPECT_EQ(scheduleInvalidationsForRules(document(),
                                           "body div { background: green}"),
             RuleSetInvalidationsScheduled);
   document().view()->updateAllLifecyclePhases();
   afterCount = styleEngine().styleForElementCount();
   EXPECT_EQ(2u, afterCount - beforeCount);
 
   EXPECT_EQ(
       scheduleInvalidationsForRules(document(), "div * { background: green}"),
       RuleSetInvalidationFullRecalc);
+  document().view()->updateAllLifecyclePhases();
+
+  beforeCount = styleEngine().styleForElementCount();
+  EXPECT_EQ(
+      scheduleInvalidationsForRules(document(), "#i b { background: green}"),
+      RuleSetInvalidationsScheduled);
+  document().view()->updateAllLifecyclePhases();
+  afterCount = styleEngine().styleForElementCount();
+  EXPECT_EQ(1u, afterCount - beforeCount);
+}
+
+TEST_F(StyleEngineTest, RuleSetInvalidationClass) {
+  document().body()->setInnerHTML(
+      "<div class='container'>"
+      "  <div class='x'></div>"
+      "</div>"
+      "<div class='x'></div>"
+      "<div class='x'></div>"
+      "<div class='x'></div>");
+
+  document().view()->updateAllLifecyclePhases();
+
+  unsigned beforeCount = styleEngine().styleForElementCount();
+  EXPECT_EQ(
+      scheduleInvalidationsForRules(document(), ".x { background: green }"),
+      RuleSetInvalidationsScheduled);
+  document().view()->updateAllLifecyclePhases();
+  unsigned afterCount = styleEngine().styleForElementCount();
+  EXPECT_EQ(4u, afterCount - beforeCount);
+
+  beforeCount = afterCount;
+  EXPECT_EQ(scheduleInvalidationsForRules(
+                document(), ".container .x { background: green }"),
+            RuleSetInvalidationsScheduled);
+  document().view()->updateAllLifecyclePhases();
+  afterCount = styleEngine().styleForElementCount();
+  EXPECT_EQ(1u, afterCount - beforeCount);
 }
 
 TEST_F(StyleEngineTest, RuleSetInvalidationHost) {
   document().body()->setInnerHTML("<div id=nohost></div><div id=host></div>");
   Element* host = document().getElementById("host");
   ASSERT_TRUE(host);
 
   ShadowRootInit init;
   init.setMode("open");
   ShadowRoot* shadowRoot = host->attachShadow(
@@ skipping 190 matching lines @@
 
   unsigned afterCount = styleEngine().styleForElementCount();
   EXPECT_EQ(0u, afterCount - beforeCount);
 
   ASSERT_TRUE(t1->computedStyle());
   EXPECT_EQ(makeRGB(0, 128, 0),
             t1->computedStyle()->visitedDependentColor(CSSPropertyColor));
 }
 
 }  // namespace blink