Move logic of recording main thread scrolling reasons from cc to blink::ScrollManager

third_party/WebKit/Source/core/input/EventHandlerTest.cpp

 // Copyright 2015 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/input/EventHandler.h"
 
 #include <memory>
 #include "core/dom/Document.h"
 #include "core/dom/Range.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/loader/EmptyClients.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/Page.h"
 #include "core/testing/DummyPageHolder.h"
+#include "platform/testing/HistogramTester.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
 
 class EventHandlerTest : public ::testing::Test {
  protected:
   void SetUp() override;
 
   Page& page() const { return m_dummyPageHolder->page(); }
   Document& document() const { return m_dummyPageHolder->document(); }
@@ skipping 43 matching lines @@
                       WebInputEvent::NoModifiers,
                       TimeTicks::Now().InSeconds()) {
     clickCount = clickCountParam;
     button = buttonParam;
     setPositionInWidget(positionParam.x(), positionParam.y());
     setPositionInScreen(positionParam.x(), positionParam.y());
     m_frameScale = 1;
   }
 };
 
+class ScrollBeginEventBuilder : public WebGestureEvent {
+ public:
+  ScrollBeginEventBuilder(IntPoint position,
+                          FloatPoint delta,
+                          WebGestureDevice device)
+      : WebGestureEvent() {
+    m_type = WebInputEvent::GestureScrollBegin;
+    x = globalX = position.x();
+    y = globalY = position.y();
+    data.scrollBegin.deltaYHint = delta.y();
+    sourceDevice = device;
+    m_frameScale = 1;
+  }
+};
+
+class ScrollEndEventBuilder : public WebGestureEvent {
+ public:
+  ScrollEndEventBuilder() : WebGestureEvent() {
+    m_type = WebInputEvent::GestureScrollEnd;
+    m_frameScale = 1;
+  }
+};
+
 void EventHandlerTest::SetUp() {
   m_dummyPageHolder = DummyPageHolder::create(IntSize(300, 400));
 }
 
 void EventHandlerTest::setHtmlInnerHTML(const char* htmlContent) {
   document().documentElement()->setInnerHTML(String::fromUTF8(htmlContent));
   document().view()->updateAllLifecyclePhases();
 }
 
 TEST_F(EventHandlerTest, dragSelectionAfterScroll) {
@@ skipping 362 matching lines @@
       WebInputEvent::MouseUp, WebFloatPoint(100, 50), WebFloatPoint(200, 250),
       WebPointerProperties::Button::Left, 1, WebInputEvent::NoModifiers,
       TimeTicks::Now().InSeconds());
   mouseUpEvent.setFrameScale(1);
   document().frame()->eventHandler().dragSourceEndedAt(mouseUpEvent,
                                                        DragOperationNone);
 
   // This test passes if it doesn't crash.
 }
 
+TEST_F(EventHandlerTest, NonCompositedMainThreadScrollingReasonTest) {
+  setHtmlInnerHTML(
+      "<style>.box { overflow:scroll; width: 100px; height: 100px; }"
+      " .translucent { opacity: 0.5; }"
+      " .spacer { height: 1000px; }"
+      " .composited { will-change: transform; }"
+      " body { height: 2000px; width: 1000px; } "
+      "</style>"
+      "<div class='translucent box'><div class='spacer'></div></div>");
+
+  page().settings().setAcceleratedCompositingEnabled(true);
+  document().view()->setParentVisible(true);
+  document().view()->setSelfVisible(true);
+  document().view()->updateAllLifecyclePhases();
+
+  HistogramTester histogramTester;
+  // Test wheel scroll.
+  ScrollBeginEventBuilder wheelScrollBegin(
+      IntPoint(50, 50), FloatPoint(0.f, 1.f), WebGestureDeviceTouchpad);
+  ScrollEndEventBuilder wheelScrollEnd;
+  document().frame()->eventHandler().handleGestureEvent(wheelScrollBegin);
+  document().frame()->eventHandler().handleGestureEvent(wheelScrollEnd);
+  histogramTester.expectBucketCount("Renderer4.MainThreadWheelScrollReason", 17,
+                                    1);
+  histogramTester.expectBucketCount("Renderer4.MainThreadWheelScrollReason", 19,
+                                    1);
+
+  // Test touch scroll.
+  ScrollBeginEventBuilder touchScrollBegin(
+      IntPoint(50, 50), FloatPoint(0.f, 1.f), WebGestureDeviceTouchscreen);
+  ScrollEndEventBuilder touchScrollEnd;
+  document().frame()->eventHandler().handleGestureEvent(touchScrollBegin);
+  document().frame()->eventHandler().handleGestureEvent(touchScrollEnd);
+  histogramTester.expectBucketCount("Renderer4.MainThreadGestureScrollReason",
+                                    17, 1);
+
+  document().frame()->eventHandler().handleGestureEvent(touchScrollBegin);
+  document().frame()->eventHandler().handleGestureEvent(touchScrollEnd);
+  histogramTester.expectBucketCount("Renderer4.MainThreadGestureScrollReason",
+                                    17, 2);
+}
+

[bokan, 2017/04/06 21:45:09]

Please add a case with some nested scrollers, an example:

A  <--NonCompositedReasonA
  B  <--Composited
    C  <--NonCompositingReasonB

To make sure we report both A and B

As well as a case in which all the nested scrollers are composited, make sure we
don't report anything.

Another good one would be to make sure we don't report anything if there's non
scrollable boxes either in between scrollers, or there are no scrollers at all.

[yigu, 2017/04/07 16:35:32]

Done.

 class TooltipCapturingChromeClient : public EmptyChromeClient {
  public:
   TooltipCapturingChromeClient() {}
 
   void setToolTip(LocalFrame&, const String& str, TextDirection) override {
     m_lastToolTip = str;
   }
 
   String& lastToolTip() { return m_lastToolTip; }
 
@@ skipping 40 matching lines @@
       WebInputEvent::MouseLeave, WebFloatPoint(0, 0), WebFloatPoint(0, 0),
       WebPointerProperties::Button::NoButton, 0, WebInputEvent::NoModifiers,
       TimeTicks::Now().InSeconds());
   mouseLeaveEvent.setFrameScale(1);
   document().frame()->eventHandler().handleMouseLeaveEvent(mouseLeaveEvent);
 
   EXPECT_EQ(WTF::String(), lastToolTip());
 }
 
 }  // namespace blink