Add flag for enabling/disabling video fullscreen detection

third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetectorTest.cpp

Index: third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetectorTest.cpp
diff --git a/third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetectorTest.cpp b/third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetectorTest.cpp
index 9da6eecebef2ea5526cc9fafe66f85c41a25b055..0f78b0034413eb98521a5abb0f9633b047830f18 100644
--- a/third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetectorTest.cpp
+++ b/third_party/WebKit/Source/core/html/MediaCustomControlsFullscreenDetectorTest.cpp
@@ -7,6 +7,7 @@
 #include "core/EventTypeNames.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/testing/DummyPageHolder.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/IntRect.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -25,6 +26,11 @@ struct TestParam {
 class MediaCustomControlsFullscreenDetectorTest : public ::testing::Test {
  protected:
   void SetUp() override {
+    m_originalVideoFullscreenDetectionEnabled =
+        RuntimeEnabledFeatures::videoFullscreenDetectionEnabled();
+
+    RuntimeEnabledFeatures::setVideoFullscreenDetectionEnabled(true);
+
     m_pageHolder = DummyPageHolder::create();
     m_newPageHolder = DummyPageHolder::create();
 
@@ -32,6 +38,11 @@ class MediaCustomControlsFullscreenDetectorTest : public ::testing::Test {
     document().body()->appendChild(&videoElement());
   }
 
+  void TearDown() override {
+    RuntimeEnabledFeatures::setVideoFullscreenDetectionEnabled(
+        m_originalVideoFullscreenDetectionEnabled);
+  }
+
   HTMLVideoElement& videoElement() const { return *m_video; }
   MediaCustomControlsFullscreenDetector& fullscreenDetector() const {
     return *videoElement().m_customControlsFullscreenDetector;
@@ -65,6 +76,8 @@ class MediaCustomControlsFullscreenDetectorTest : public ::testing::Test {
   std::unique_ptr<DummyPageHolder> m_pageHolder;
   std::unique_ptr<DummyPageHolder> m_newPageHolder;
   Persistent<HTMLVideoElement> m_video;
+
+  bool m_originalVideoFullscreenDetectionEnabled;
 };
 
 TEST_F(MediaCustomControlsFullscreenDetectorTest, computeIsDominantVideo) {