Reduce rectangle merges when doing region-based hit test on text boxes

third_party/WebKit/Source/core/layout/LayoutInlineTest.cpp

 // Copyright 2014 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/layout/LayoutInline.h"
 
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 22 matching lines @@
 
   LayoutInline* splitInlinePart2 = toLayoutInline(block->continuation());
   ASSERT_TRUE(splitInlinePart2);
   ASSERT_TRUE(splitInlinePart2->firstChild());
   EXPECT_EQ(splitInlinePart2->firstChild(),
             getLayoutObjectByElementId("after"));
   EXPECT_FALSE(splitInlinePart2->firstChild()->nextSibling());
   EXPECT_FALSE(splitInlinePart2->continuation());
 }
 
+TEST_F(LayoutInlineTest, RegionHitTest) {
+  setBodyInnerHTML(
+      "<div><span id='lotsOfBoxes'>"
+      "This is a test line<br>This is a test line<br>This is a test line<br>"
+      "This is a test line<br>This is a test line<br>This is a test line<br>"
+      "This is a test line<br>This is a test line<br>This is a test line<br>"
+      "This is a test line<br>This is a test line<br>This is a test line<br>"
+      "This is a test line<br>This is a test line<br>This is a test line<br>"
+      "This is a test line<br>This is a test line<br>This is a test line<br>"
+      "</span></div>");
+
+  document().view()->updateAllLifecyclePhases();
+
+  LayoutInline* lotsOfBoxes =
+      toLayoutInline(getLayoutObjectByElementId("lotsOfBoxes"));
+  ASSERT_TRUE(lotsOfBoxes);
+
+  HitTestRequest hitRequest(HitTestRequest::TouchEvent |
+                            HitTestRequest::ListBased);
+  LayoutPoint hitLocation(2, 5);
+  HitTestResult hitResult(hitRequest, hitLocation, 2, 1, 2, 1);
+  LayoutPoint hitOffset;
+
+  bool hitOutcome = lotsOfBoxes->hitTestCulledInline(
+      hitResult, hitResult.hitTestLocation(), hitOffset);
+  // Assert checks that we both hit something and that the area covered
+  // by "something" totally contains the hit region.
+  EXPECT_TRUE(hitOutcome);
+}
+
 }  // namespace blink