Bug 1569135 Fix --screenshot r=kmag

This patch ressurects HiddenFrame.jsm and uses it when handling
the --screenshot command line argument to load the requested page
in a content process.  The actual logic for grabbing the image is
also ported to a JSWindowActor.  The test for this feature remains
suboptimal as described in the bug.

Differential Revision: https://phabricator.services.mozilla.com/D40148

--HG--
rename : browser/components/shell/HeadlessShell.jsm => browser/components/shell/ScreenshotChild.jsm
extra : moz-landing-system : lando

browser/base/content/test/static/browser_all_files_referenced.js

@@ -103,9 +103,6 @@ var whitelist = [
   { file: "resource://gre/res/fonts/mathfontSTIXGeneral.properties" },
   { file: "resource://gre/res/fonts/mathfontUnicode.properties" },
 
-  // Needed by HiddenFrame.jsm, but can't be packaged test-only
-  { file: "chrome://global/content/win.xul" },
-
   // The l10n build system can't package string files only for some platforms.
   {
     file:

browser/base/content/test/static/browser_parsable_css.js

@@ -397,7 +397,7 @@ add_task(async function checkAllTheCSS() {
   // chrome URI so that it's allowed to load and parse any styles.
   let testFile = getRootDirectory(gTestPath) + "dummy_page.html";
   let HiddenFrame = ChromeUtils.import(
-    "resource://testing-common/HiddenFrame.jsm",
+    "resource://gre/modules/HiddenFrame.jsm",
     {}
   ).HiddenFrame;
   let hiddenFrame = new HiddenFrame();

browser/components/extensions/test/browser/browser_ext_webRequest.js

@@ -5,7 +5,7 @@
 /* import-globals-from ../../../../../toolkit/components/extensions/test/mochitest/head_webrequest.js */
 loadTestSubscript("head_webrequest.js");
 
-ChromeUtils.import("resource://testing-common/HiddenFrame.jsm", this);
+ChromeUtils.import("resource://gre/modules/HiddenFrame.jsm", this);
 const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
 
 SimpleTest.requestCompleteLog();

browser/components/shell/HeadlessShell.jsm

@@ -4,16 +4,38 @@
 
 "use strict";
 
-var EXPORTED_SYMBOLS = ["HeadlessShell"];
+var EXPORTED_SYMBOLS = ["HeadlessShell", "ScreenshotParent"];
 
-const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+const { E10SUtils } = ChromeUtils.import(
+  "resource://gre/modules/E10SUtils.jsm"
+);
+const { HiddenFrame } = ChromeUtils.import(
+  "resource://gre/modules/HiddenFrame.jsm"
+);
 const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
+const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 // Refrences to the progress listeners to keep them from being gc'ed
 // before they are called.
-const progressListeners = new Map();
+const progressListeners = new Set();
 
-function loadContentWindow(webNavigation, url, principal) {
+class ScreenshotParent extends JSWindowActorParent {
+  takeScreenshot(params) {
+    return this.sendQuery("TakeScreenshot", params);
+  }
+}
+
+ChromeUtils.registerWindowActor("Screenshot", {
+  parent: {
+    moduleURI: "resource:///modules/HeadlessShell.jsm",
+  },
+  child: {
+    moduleURI: "resource:///modules/ScreenshotChild.jsm",
+    messages: ["TakeScreenshot"],
+  },
+});
+
+function loadContentWindow(browser, url) {
   let uri;
   try {
     uri = Services.io.newURI(url);
@@ -22,21 +44,20 @@ function loadContentWindow(webNavigation, url, principal) {
     Cu.reportError(msg);
     return Promise.reject(new Error(msg));
   }
+
+  const principal = Services.scriptSecurityManager.getSystemPrincipal();
   return new Promise((resolve, reject) => {
     let loadURIOptions = {
       triggeringPrincipal: principal,
+      remoteType: E10SUtils.getRemoteTypeForURI(url, true, false),
     };
-    webNavigation.loadURI(uri.spec, loadURIOptions);
+    browser.loadURI(uri.spec, loadURIOptions);
-    let docShell = webNavigation
+    let { webProgress } = browser;
-      .QueryInterface(Ci.nsIInterfaceRequestor)
+
-      .getInterface(Ci.nsIDocShell);
-    let webProgress = docShell
-      .QueryInterface(Ci.nsIInterfaceRequestor)
-      .getInterface(Ci.nsIWebProgress);
     let progressListener = {
       onLocationChange(progress, request, location, flags) {
         // Ignore inner-frame events
-        if (progress != webProgress) {
+        if (!progress.isTopLevel) {
           return;
         }
         // Ignore events that don't change the document
@@ -47,23 +68,17 @@ function loadContentWindow(webNavigation, url, principal) {
         if (location.spec == "about:blank" && uri.spec != "about:blank") {
           return;
         }
-        let contentWindow = docShell.domWindow;
+
         progressListeners.delete(progressListener);
         webProgress.removeProgressListener(progressListener);
-        contentWindow.addEventListener(
+        resolve();
-          "load",
-          event => {
-            resolve(contentWindow);
-          },
-          { once: true }
-        );
       },
       QueryInterface: ChromeUtils.generateQI([
         "nsIWebProgressListener",
         "nsISupportsWeakReference",
       ]),
     };
-    progressListeners.set(progressListener, progressListener);
+    progressListeners.add(progressListener);
     webProgress.addProgressListener(
       progressListener,
       Ci.nsIWebProgress.NOTIFY_LOCATION
@@ -79,56 +94,37 @@ async function takeScreenshot(
   path,
   url
 ) {
+  let frame;
   try {
-    var windowlessBrowser = Services.appShell.createWindowlessBrowser(false);
+    frame = new HiddenFrame();
-    // nsIWindowlessBrowser inherits from nsIWebNavigation.
+    let windowlessBrowser = await frame.get();
-    let contentWindow = await loadContentWindow(
+
-      windowlessBrowser,
+    let doc = windowlessBrowser.document;
-      url,
+    let browser = doc.createXULElement("browser");
-      Services.scriptSecurityManager.getSystemPrincipal()
+    browser.setAttribute("remote", "true");
+    browser.setAttribute("type", "content");
+    browser.setAttribute(
+      "style",
+      `width: ${contentWidth}px; min-width: ${contentWidth}px; height: ${contentHeight}px; min-height: ${contentHeight}px;`
     );
-    contentWindow.resizeTo(contentWidth, contentHeight);
+    doc.documentElement.appendChild(browser);
 
-    let canvas = contentWindow.document.createElementNS(
+    await loadContentWindow(browser, url);
-      "http://www.w3.org/1999/xhtml",
+
-      "html:canvas"
+    let actor = browser.browsingContext.currentWindowGlobal.getActor(
-    );
+      "Screenshot"
-    let context = canvas.getContext("2d");
-    let width = fullWidth
-      ? contentWindow.innerWidth +
-        contentWindow.scrollMaxX -
-        contentWindow.scrollMinX
-      : contentWindow.innerWidth;
-    let height = fullHeight
-      ? contentWindow.innerHeight +
-        contentWindow.scrollMaxY -
-        contentWindow.scrollMinY
-      : contentWindow.innerHeight;
-    canvas.width = width;
-    canvas.height = height;
-    context.drawWindow(
-      contentWindow,
-      0,
-      0,
-      width,
-      height,
-      "rgb(255, 255, 255)"
     );
+    let blob = await actor.takeScreenshot({
+      fullWidth,
+      fullHeight,
+    });
 
-    function getBlob() {
+    let reader = await new Promise(resolve => {
-      return new Promise(resolve => canvas.toBlob(resolve));
+      let fr = new FileReader();
-    }
+      fr.onloadend = () => resolve(fr);
+      fr.readAsArrayBuffer(blob);
+    });
 
-    function readBlob(blob) {
-      return new Promise(resolve => {
-        let reader = new FileReader();
-        reader.onloadend = () => resolve(reader);
-        reader.readAsArrayBuffer(blob);
-      });
-    }
-
-    let blob = await getBlob();
-    let reader = await readBlob(blob);
     await OS.File.writeAtomic(path, new Uint8Array(reader.result), {
       flush: true,
     });
@@ -136,8 +132,8 @@ async function takeScreenshot(
   } catch (e) {
     dump("Failure taking screenshot: " + e + "\n");
   } finally {
-    if (windowlessBrowser) {
+    if (frame) {
-      windowlessBrowser.close();
+      frame.destroy();
     }
   }
 }

browser/components/shell/ScreenshotChild.jsm

@@ -0,0 +1,50 @@
+"use strict";
+
+const EXPORTED_SYMBOLS = ["ScreenshotChild"];
+
+class ScreenshotChild extends JSWindowActorChild {
+  receiveMessage(message) {
+    if (message.name == "TakeScreenshot") {
+      return this.takeScreenshot(message.data);
+    }
+    return null;
+  }
+
+  async takeScreenshot(params) {
+    if (this.document.readyState != "complete") {
+      await new Promise(resolve =>
+        this.contentWindow.addEventListener("load", resolve, { once: true })
+      );
+    }
+
+    let { fullWidth, fullHeight } = params;
+    let { contentWindow } = this;
+
+    let canvas = contentWindow.document.createElementNS(
+      "http://www.w3.org/1999/xhtml",
+      "html:canvas"
+    );
+    let context = canvas.getContext("2d");
+    let width = contentWindow.innerWidth;
+    let height = contentWindow.innerHeight;
+    if (fullWidth) {
+      width += contentWindow.scrollMaxX - contentWindow.scrollMinX;
+    }
+    if (fullHeight) {
+      height += contentWindow.scrollMaxY - contentWindow.scrollMinY;
+    }
+
+    canvas.width = width;
+    canvas.height = height;
+    context.drawWindow(
+      contentWindow,
+      0,
+      0,
+      width,
+      height,
+      "rgb(255, 255, 255)"
+    );
+
+    return new Promise(resolve => canvas.toBlob(resolve));
+  }
+}

browser/components/shell/moz.build

@@ -49,6 +49,7 @@ if SOURCES:
 
 EXTRA_JS_MODULES += [
     'HeadlessShell.jsm',
+    'ScreenshotChild.jsm',
     'ShellService.jsm',
 ]
 

browser/components/uitour/test/browser_no_tabs.js

@@ -4,7 +4,7 @@
 "use strict";
 
 var HiddenFrame = ChromeUtils.import(
-  "resource://testing-common/HiddenFrame.jsm",
+  "resource://gre/modules/HiddenFrame.jsm",
   {}
 ).HiddenFrame;
 

toolkit/modules/moz.build

@@ -147,7 +147,6 @@ BROWSER_CHROME_MANIFESTS += ['tests/browser/browser.ini']
 MOCHITEST_CHROME_MANIFESTS += ['tests/chrome/chrome.ini']
 
 TESTING_JS_MODULES += [
-    'HiddenFrame.jsm',
     'tests/modules/MockDocument.jsm',
     'tests/modules/PromiseTestUtils.jsm',
     'tests/modules/Task.jsm',
@@ -194,6 +193,7 @@ EXTRA_JS_MODULES += [
     'GMPExtractorWorker.js',
     'GMPInstallManager.jsm',
     'GMPUtils.jsm',
+    'HiddenFrame.jsm',
     'Http.jsm',
     'IgnoreLists.jsm',
     'IndexedDB.jsm',