Add virtual tests suite for kWheelEventRegions feature

- Added WheelEventRegions runtime feature flag.
- Changed mouse coordinates in wheel-event-target.html test to
  accommodate for rounding per [1].
- Changed wheel event handler region in layer-scroll-rects-get.js
  to enforce not empty wheel handler region.

[1] https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/renderer/platform/graphics/paint/paint_controller.cc;l=49;bpv=1;bpt=1?q=RecordHitTestData&ss=chromium%2Fchromium%2Fsrc

Bug: 1136588
Change-Id: I437c87d7c8a53f107f676b647d737ce1de7827f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521354Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Sam Fortiner <samfort@microsoft.com>
Commit-Queue: Olga Gerchikov <gerchiko@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#827435}

content/child/runtime_features.cc

@@ -317,6 +317,7 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
     {wf::EnableParseUrlProtocolHandler,
      blink::features::kWebAppEnableProtocolHandlers},
     {wf::EnableWebID, features::kWebID},
+    {wf::EnableWheelEventRegions, features::kWheelEventRegions},
   };
   for (const auto& mapping : blinkFeatureToBaseFeatureMapping) {
     SetRuntimeFeatureFromChromiumFeature(

third_party/blink/public/platform/web_runtime_features.h

@@ -177,6 +177,7 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableWebXRLightEstimation(bool);
   BLINK_PLATFORM_EXPORT static void EnableWebXRPlaneDetection(bool);
   BLINK_PLATFORM_EXPORT static void EnableWebXRViewportScale(bool);
+  BLINK_PLATFORM_EXPORT static void EnableWheelEventRegions(bool);
   BLINK_PLATFORM_EXPORT static void ForceOverlayFullscreenVideo(bool);
   BLINK_PLATFORM_EXPORT static void EnableTimerThrottlingForBackgroundTabs(
       bool);

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -413,6 +413,10 @@ void WebRuntimeFeatures::EnableWebXRViewportScale(bool enable) {
   RuntimeEnabledFeatures::SetWebXRViewportScaleEnabled(enable);
 }
 
+void WebRuntimeFeatures::EnableWheelEventRegions(bool enable) {
+  RuntimeEnabledFeatures::SetWheelEventRegionsEnabled(enable);
+}
+
 void WebRuntimeFeatures::EnablePresentationAPI(bool enable) {
   RuntimeEnabledFeatures::SetPresentationEnabled(enable);
 }

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -2252,6 +2252,9 @@
       depends_on: ["WebXRARModule"],
       status: "experimental",
     },
+    {
+      name: "WheelEventRegions",
+    },
     // Extends window placement functionality for multi-screen devices. Also
     // exposes requisite information about displays connected to the device.
     {

third_party/blink/web_tests/VirtualTestSuites

@@ -768,5 +768,31 @@
     "bases": ["fast/scrolling/scrollbars"],
     "args": ["--enable-features=ScrollUnification",
              "--enable-threaded-compositing"]
+  },
+  {
+    "prefix": "wheel-event-regions",
+    "bases": ["fast/dom/shadow/wheel-event-in-shadow-dom.html",
+              "fast/dom/shadow/wheel-event-on-input-in-shadow-dom.html",
+              "fast/compositor-wheel-scroll-latching",
+              "fast/events/move-element-with-wheel-and-touch-event-listeners.html",
+              "fast/events/iframe-mousewheel.html",
+              "fast/events/platform-wheelevent-paging-xy-in-scrolling-div.html",
+              "fast/events/platform-wheelevent-paging-xy-in-scrolling-page.html",
+              "fast/events/platform-wheelevent-paging-x-in-scrolling-page.html",
+              "fast/events/platform-wheelevent-paging-y-in-scrolling-page.html",
+              "fast/events/platform-wheelevent-paging-x-in-non-scrolling-div.html",
+              "fast/events/platform-wheelevent-paging-y-in-non-scrolling-div.html",
+              "fast/events/platform-wheelevent-paging-x-in-non-scrolling-page.html",
+              "fast/events/platform-wheelevent-paging-y-in-non-scrolling-page.html",
+              "fast/events/wheel",
+              "fast/scrolling/document-level-wheel-event-listener-passive-by-default.html",
+              "http/tests/devtools/layers/layer-scroll-rects-get.js",
+              "pointer-lock/wheel-event-cancelable.html",
+              "pointer-lock/wheel-event-target.html",
+              "scrollbars/scrollevent-iframe-no-scrolling-wheel.html",
+              "scrollingcoordinator/donot-compute-non-fast-scrollable-region-for-hidden-frames.html",
+              "scrollingcoordinator/plugin-with-wheel-handler.html",
+              "scrollingcoordinator/non-fast-scrollable-region-nested.html"],
+    "args": ["--enable-features=WheelEventRegions"]
   }
 ]

third_party/blink/web_tests/http/tests/devtools/layers/layer-scroll-rects-get.js

@@ -6,7 +6,7 @@
   TestRunner.addResult(`Tests scroll rectangles support in in Layers3DViewxScroll rectangles\n`);
   await TestRunner.loadModule('layers_test_runner');
   await TestRunner.loadHTML(`
-      <div style="transform: translateZ(100px);" onmousewheel=""></div>
+      <div style="transform: translateZ(100px);height:20px;width:30px;" onmousewheel=""></div>
       <div id="touchable" style="transform:translateZ(100px);height:20px;width:20px;overflow:scroll;">
           <div style="height:40px;width:40px;"></div>
       </div>

third_party/blink/web_tests/pointer-lock/wheel-event-target.html

@@ -36,8 +36,8 @@
       testObject.unreached_func("wheel event should not fire on element with id = text!"));
 
    let rect = textDiv.getBoundingClientRect();
-   let x = rect.left;
-   let y = rect.top;
+   let x = rect.left + 5;
+   let y = rect.top + 5;
    await mouseMoveTo(x, y);
    await smoothScrollWithXY(5, 5, x, y, GestureSourceType.MOUSE_INPUT, SPEED_INSTANT);
 

third_party/blink/web_tests/virtual/wheel-event-regions/README.md

+This directory is dedicated for testing the "WheelEventRegions" feature.

third_party/blink/web_tests/virtual/wheel-event-regions/README.txt

+This directory is dedicated for testing the "WheelEventRegions" feature.

third_party/blink/web_tests/virtual/wheel-event-regions/http/tests/devtools/layers/layer-scroll-rects-get-expected.txt

+Tests scroll rectangles support in in Layers3DViewxScroll rectangles
+
+Scroll rectangles
+{
+    0 : {
+        rect : {
+            height : 20
+            width : 30
+            x : 0
+            y : 0
+        }
+        type : "WheelEventHandler"
+    }
+}
+{
+    0 : {
+        rect : {
+            height : 20
+            width : 20
+            x : 0
+            y : 0
+        }
+        type : "TouchEventHandler"
+    }
+}
+{
+    0 : {
+        rect : {
+            height : 40
+            width : 40
+            x : 0
+            y : 0
+        }
+        type : "TouchEventHandler"
+    }
+}
+

tools/metrics/histograms/enums.xml

@@ -44804,6 +44804,7 @@ from previous Chrome versions.
   <int value="698273842" label="SyncSendTabToSelf:enabled"/>
   <int value="698809951" label="WebRtcHWVP8Encoding:enabled"/>
   <int value="699149897" label="ContentSuggestionsDebugLog:disabled"/>
+  <int value="700346797" label="WheelEventRegions:enabled"/>
   <int value="701766325" label="PerNavigationMojoInterface:enabled"/>
   <int value="703469777" label="AndroidNightModeTabReparenting:enabled"/>
   <int value="705407202" label="AutofillSaveCardImprovedUserConsent:disabled"/>
@@ -45066,6 +45067,7 @@ from previous Chrome versions.
   <int value="977140835" label="OmniboxMostVisitedTiles:disabled"/>
   <int value="977968353" label="WebUITabStrip:disabled"/>
   <int value="978712907" label="PrintServerUi:disabled"/>
+  <int value="979397813" label="WheelEventRegions:disabled"/>
   <int value="979445973" label="OmniboxSpareRenderer:enabled"/>
   <int value="980396200" label="enable-new-korean-ime"/>
   <int value="981818901" label="AppBanners:enabled"/>