Embedded media: Rotate to fullscreen

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

Index: third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp b/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
index 90a86f6e9897604811faebcbd56eb3150fb0f959..82e313ec93509780da9f1457ebff991bac3dd932 100644
--- a/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLVideoElement.cpp
@@ -30,9 +30,14 @@
 #include "core/CSSPropertyNames.h"
 #include "core/HTMLNames.h"
 #include "core/dom/Attribute.h"
+#include "core/dom/ClientRect.h"
 #include "core/dom/Document.h"
+#include "core/dom/DocumentUserGestureToken.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/Fullscreen.h"
+#include "core/dom/ResizeObserver.h"
+#include "core/dom/ResizeObserverCallback.h"
+#include "core/dom/ResizeObserverEntry.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/LocalDOMWindow.h"
@@ -53,8 +58,53 @@ namespace blink {
 
 using namespace HTMLNames;
 
+class HTMLVideoElementResizeObserverCallback final
+    : public ResizeObserverCallback {
+ public:
+  explicit HTMLVideoElementResizeObserverCallback(HTMLVideoElement* video)
+      : m_video(video), m_prevOrientationLandscape(false) {
+    DCHECK(video);
+  }
+
+  ~HTMLVideoElementResizeObserverCallback() override = default;
+
+  void handleEvent(const HeapVector<Member<ResizeObserverEntry>>& entries,
+                   ResizeObserver* observer) override {
+    if (!m_video->document().settings() ||
+        !m_video->document().settings()->getEmbeddedMediaExperienceEnabled())
+      return;
+
+    DCHECK_EQ(1u, entries.size());
+    float documentWidth = entries[0]->contentRect()->width();
+    float documentHeight = entries[0]->contentRect()->height();
+
+    if (!m_prevOrientationLandscape && documentWidth > documentHeight) {
+      UserGestureIndicator gesture(
+          DocumentUserGestureToken::create(&m_video->document()));
+      m_video->webkitEnterFullscreen();
+    }
+
+    m_prevOrientationLandscape = documentWidth > documentHeight;
+  }
+
+  DEFINE_INLINE_TRACE() {
+    visitor->trace(m_video);
+    ResizeObserverCallback::trace(visitor);
+  }
+
+ private:
+  Member<HTMLVideoElement> m_video;
+  bool m_prevOrientationLandscape;
+};
+
 inline HTMLVideoElement::HTMLVideoElement(Document& document)
-    : HTMLMediaElement(videoTag, document) {
+    : HTMLMediaElement(videoTag, document),
+      m_customControlsFullscreenDetector(
+          new MediaCustomControlsFullscreenDetector(*this)),
+      m_resizeObserver(ResizeObserver::create(
+          document,
+          new HTMLVideoElementResizeObserverCallback(this))) {
+  m_resizeObserver->observe(document.documentElement());
   if (document.settings()) {
     m_defaultPosterURL =
         AtomicString(document.settings()->getDefaultVideoPosterURL());
@@ -76,10 +126,12 @@ HTMLVideoElement* HTMLVideoElement::create(Document& document) {
 DEFINE_TRACE(HTMLVideoElement) {
   visitor->trace(m_imageLoader);
   visitor->trace(m_customControlsFullscreenDetector);
+  visitor->trace(m_resizeObserver);
   HTMLMediaElement::trace(visitor);
 }
 
 void HTMLVideoElement::contextDestroyed(ExecutionContext* context) {
+  m_resizeObserver.clear();
   if (m_customControlsFullscreenDetector)
     m_customControlsFullscreenDetector->contextDestroyed();