JavaScript dialogs cause a page to lose fullscreen.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 6f3dcbd9028d67011b1ff5324af3d7aed06b3e49..c0f3e0c46fa98edfcc94a3a514edf0b41b7aa043 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -448,6 +448,7 @@ class CONTENT_EXPORT WebContentsImpl
   void StopFinding(StopFindAction action) override;
   bool WasRecentlyAudible() override;
   void GetManifest(const GetManifestCallback& callback) override;
+  bool IsFullscreenForCurrentTab() const override;
   void ExitFullscreen(bool will_cause_resize) override;
   void ResumeLoadingCreatedWebContents() override;
   void OnPasswordInputShownOnHttp() override;
@@ -705,7 +706,8 @@ class CONTENT_EXPORT WebContentsImpl
                           bool user_gesture,
                           bool last_unlocked_by_target,
                           bool privileged) override;
-  bool IsFullscreenForCurrentTab() const override;
+  // The following function is already listed under WebContents overrides:
+  // bool IsFullscreenForCurrentTab() const override;

[Matt Giuca, 2017/06/09 06:16:37]

Shouldn't have commented-out lines of code.

How about just "// IsFullscreenForCurrentTab is already ...."

[Avi (use Gerrit), 2017/06/09 14:36:23]

This is paralleling lines 689, etc, above.

   blink::WebDisplayMode GetDisplayMode(
       RenderWidgetHostImpl* render_widget_host) const override;
   void LostCapture(RenderWidgetHostImpl* render_widget_host) override;
@@ -906,6 +908,8 @@ class CONTENT_EXPORT WebContentsImpl
                            CrossSiteIframeAccessibility);
   FRIEND_TEST_ALL_PREFIXES(WebContentsImplBrowserTest,
                            JavaScriptDialogsInMainAndSubframes);
+  FRIEND_TEST_ALL_PREFIXES(WebContentsImplBrowserTest,
+                           DialogsFromJavaScriptEndFullscreen);
   FRIEND_TEST_ALL_PREFIXES(RenderFrameHostImplBrowserTest,
                            IframeBeforeUnloadParentHang);
   FRIEND_TEST_ALL_PREFIXES(RenderFrameHostImplBrowserTest,