[screen-orientation] Don't always unlock when fullscreen state is left.

content/browser/screen_orientation/screen_orientation_provider_android.cc

Index: content/browser/screen_orientation/screen_orientation_provider_android.cc
diff --git a/content/browser/screen_orientation/screen_orientation_provider_android.cc b/content/browser/screen_orientation/screen_orientation_provider_android.cc
index 234b6e3a2bdd57a85c9c8b207275bd3648c3d763..975e43bb19190ff7c8e47eb5f072e0a7f03a92bc 100644
--- a/content/browser/screen_orientation/screen_orientation_provider_android.cc
+++ b/content/browser/screen_orientation/screen_orientation_provider_android.cc
@@ -121,10 +121,18 @@ void ScreenOrientationProviderAndroid::OnOrientationChange() {
 
 void ScreenOrientationProviderAndroid::DidToggleFullscreenModeForTab(
     bool entered_fullscreen) {
-  if (lock_applied_) {
-    DCHECK(!entered_fullscreen);
-    UnlockOrientation();
-  }
+  if (!lock_applied_)
+    return;
+
+  // If fullscreen is not required in order to lock orientation, don't unlock
+  // when fullscreen state changes.
+  ContentViewCoreImpl* cvc =
+      ContentViewCoreImpl::FromWebContents(web_contents());
+  if (cvc && !cvc->IsFullscreenRequiredForOrientationLock())
+    return;
+
+  DCHECK(!entered_fullscreen);
+  UnlockOrientation();
 }
 
 bool ScreenOrientationProviderAndroid::LockMatchesCurrentOrientation(