RuleSet invalidations on single feature only, including tags.

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

Index: third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
diff --git a/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp b/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
index e62026ec9a2d63c9b05fdea6e2d35cd0caf23a9e..dce66ba0d1990ac457d707a2fbed0fb6ba93f9fc 100644
--- a/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
+++ b/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
@@ -144,7 +144,13 @@ TEST_F(StyleEngineTest, RuleSetInvalidationTypeSelectors) {
       "<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();
 
@@ -167,6 +173,43 @@ TEST_F(StyleEngineTest, RuleSetInvalidationTypeSelectors) {
   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) {