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

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

Index: third_party/WebKit/Source/core/layout/LayoutInline.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutInline.cpp b/third_party/WebKit/Source/core/layout/LayoutInline.cpp
index d8abdb06ea2e634593a42aa87e078561dcbcca34..19c4700cc9fb14f4411be3bbe2c604bb5de9e07f 100644
--- a/third_party/WebKit/Source/core/layout/LayoutInline.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutInline.cpp
@@ -876,12 +876,16 @@ class HitTestCulledInlinesGeneratorContext {
                                        const HitTestLocation& location)
       : m_intersected(false), m_region(region), m_location(location) {}
   void operator()(const FloatRect& rect) {
-    m_intersected = m_intersected || m_location.intersects(rect);
-    m_region.unite(enclosingIntRect(rect));
+    bool intersects = m_location.intersects(rect);
+    m_intersected = m_intersected || intersects;

[wkorman, 2017/01/04 00:36:35]

nit: could use |= here and below.

+    if (intersects)
+      m_region.unite(enclosingIntRect(rect));
   }
   void operator()(const LayoutRect& rect) {
-    m_intersected = m_intersected || m_location.intersects(rect);
-    m_region.unite(enclosingIntRect(rect));
+    bool intersects = m_location.intersects(rect);
+    m_intersected = m_intersected || intersects;
+    if (intersects)
+      m_region.unite(enclosingIntRect(rect));
   }
   bool intersected() const { return m_intersected; }