From 15dffb3ddeb6ad5c99d2d53df304d1776a791b52 Mon Sep 17 00:00:00 2001
From: loc <andy@slack-corp.com>
Date: Tue, 5 Nov 2019 16:34:45 -0500
Subject: [PATCH] fix: allow iframe-initiated HTML fullscreen to exit while in
 macOS fullscreen (#20962)

* fix: explicitly resize the contents when exiting html fullscreen while in OS fullscreen

* test: ensure HTML fullscreen toggles while in OS fullscreen
---
 shell/browser/common_web_contents_delegate.cc |  7 ++
 spec-main/chromium-spec.ts                    | 78 +++++++++++++++++++
 spec/fixtures/pages/fullscreen-ipif.html      | 15 ++++
 spec/fixtures/pages/fullscreen-oopif.html     | 19 +++++
 4 files changed, 119 insertions(+)
 create mode 100644 spec/fixtures/pages/fullscreen-ipif.html
 create mode 100644 spec/fixtures/pages/fullscreen-oopif.html

diff --git a/shell/browser/common_web_contents_delegate.cc b/shell/browser/common_web_contents_delegate.cc
index 7e80b689be..744de040a8 100644
--- a/shell/browser/common_web_contents_delegate.cc
+++ b/shell/browser/common_web_contents_delegate.cc
@@ -355,6 +355,13 @@ void CommonWebContentsDelegate::ExitFullscreenModeForTab(
     return;
   SetHtmlApiFullscreen(false);
   owner_window_->NotifyWindowLeaveHtmlFullScreen();
+
+  if (native_fullscreen_) {
+    // Explicitly trigger a view resize, as the size is not actually changing if
+    // the browser is fullscreened, too. Chrome does this indirectly from
+    // `chrome/browser/ui/exclusive_access/fullscreen_controller.cc`.
+    source->GetRenderViewHost()->GetWidget()->SynchronizeVisualProperties();
+  }
 }
 
 bool CommonWebContentsDelegate::IsFullscreenForTabOrPending(
diff --git a/spec-main/chromium-spec.ts b/spec-main/chromium-spec.ts
index 44ce99e3f8..999927271b 100644
--- a/spec-main/chromium-spec.ts
+++ b/spec-main/chromium-spec.ts
@@ -1066,3 +1066,81 @@ describe('font fallback', () => {
     if (process.platform === 'win32') { expect(fonts[0].familyName).to.be.oneOf(['Meiryo', 'Yu Gothic']) } else if (process.platform === 'darwin') { expect(fonts[0].familyName).to.equal('Hiragino Kaku Gothic ProN') }
   })
 })
+
+describe('iframe using HTML fullscreen API while window is OS-fullscreened', () => {
+  const fullscreenChildHtml = promisify(fs.readFile)(
+    path.join(fixturesPath, 'pages', 'fullscreen-oopif.html')
+  )
+  let w: BrowserWindow, server: http.Server
+
+  before(() => {
+    server = http.createServer(async (_req, res) => {
+      res.writeHead(200, { 'Content-Type': 'text/html' })
+      res.write(await fullscreenChildHtml)
+      res.end()
+    })
+
+    server.listen(8989, '127.0.0.1')
+  })
+
+  beforeEach(() => {
+    w = new BrowserWindow({
+      show: true,
+      fullscreen: true,
+      webPreferences: {
+        nodeIntegration: true,
+        nodeIntegrationInSubFrames: true
+      }
+    })
+  })
+
+  afterEach(async () => {
+    await closeAllWindows()
+    ;(w as any) = null
+    server.close()
+  })
+
+  it('can fullscreen from out-of-process iframes (OOPIFs)', done => {
+    ipcMain.once('fullscreenChange', async () => {
+      const fullscreenWidth = await w.webContents.executeJavaScript(
+        "document.querySelector('iframe').offsetWidth"
+      )
+      expect(fullscreenWidth > 0).to.be.true()
+
+      await w.webContents.executeJavaScript(
+        "document.querySelector('iframe').contentWindow.postMessage('exitFullscreen', '*')"
+      )
+
+      await new Promise(resolve => setTimeout(resolve, 500))
+
+      const width = await w.webContents.executeJavaScript(
+        "document.querySelector('iframe').offsetWidth"
+      )
+      expect(width).to.equal(0)
+
+      done()
+    })
+
+    const html =
+      '<iframe style="width: 0" frameborder=0 src="http://localhost:8989" allowfullscreen></iframe>'
+    w.loadURL(`data:text/html,${html}`)
+  })
+
+  it('can fullscreen from in-process iframes', done => {
+    ipcMain.once('fullscreenChange', async () => {
+      const fullscreenWidth = await w.webContents.executeJavaScript(
+        "document.querySelector('iframe').offsetWidth"
+      )
+      expect(fullscreenWidth > 0).to.true()
+
+      await w.webContents.executeJavaScript('document.exitFullscreen()')
+      const width = await w.webContents.executeJavaScript(
+        "document.querySelector('iframe').offsetWidth"
+      )
+      expect(width).to.equal(0)
+      done()
+    })
+
+    w.loadFile(path.join(fixturesPath, 'pages', 'fullscreen-ipif.html'))
+  })
+})
diff --git a/spec/fixtures/pages/fullscreen-ipif.html b/spec/fixtures/pages/fullscreen-ipif.html
new file mode 100644
index 0000000000..dfca5396e1
--- /dev/null
+++ b/spec/fixtures/pages/fullscreen-ipif.html
@@ -0,0 +1,15 @@
+<body>
+    <iframe style="width: 0" frameborder=0 src="fullscreen.html" allowfullscreen></iframe>
+    <script>
+        const { webFrame, ipcRenderer } = require('electron')
+        const iframe = document.querySelector('iframe')
+
+        document.addEventListener('fullscreenchange', () => {
+            ipcRenderer.send('fullscreenChange')
+        })
+
+        iframe.addEventListener('load', () => {
+            webFrame.executeJavaScript("document.querySelector('iframe').contentDocument.querySelector('video').requestFullscreen()", true)
+        })
+    </script>
+</body>
diff --git a/spec/fixtures/pages/fullscreen-oopif.html b/spec/fixtures/pages/fullscreen-oopif.html
new file mode 100644
index 0000000000..db9a24d77f
--- /dev/null
+++ b/spec/fixtures/pages/fullscreen-oopif.html
@@ -0,0 +1,19 @@
+<script>
+    const { webFrame, ipcRenderer } = require('electron')
+
+    document.addEventListener('fullscreenchange', () => {
+        ipcRenderer.send('fullscreenChange', webFrame.routingId)
+    });
+
+    window.addEventListener('message', ({ data }) => {
+        if (data === 'exitFullscreen') {
+            document.exitFullscreen()
+        }
+    })
+
+    window.addEventListener('load', () => {
+        window.focus()
+        webFrame.executeJavaScript('document.querySelector("video").requestFullscreen()', true)
+    });
+</script>
+<video></video>