ochameau

[WindowGlobalLogger] handleEvent(DOMWindowCreated)
    BrowsingContext.browserId: 4294967297
    BrowsingContext.id: 4294967297
    innerWindowId: 4294967298
    pid: undefined
    isClosed: false
    isInProcess: false
    isCurrentGlobal: true
    currentRemoteType: undefined
    hasParent: no

ochameau

Tested while executing:
  gBrowser.addTab("about:blank", {triggeringPrincipal:Services.scriptSecurityManager.getSystemPrincipal()})

[WindowGlobalLogger] handleEvent(DOMWindowCreated)
    BrowsingContext.browserId: 13
    BrowsingContext.id: 43
    innerWindowId: 36
    pid: undefined
    isClosed: false
    isInProcess: false

ochameau

Devtools Targets:

DevTools Toolbox can debug many contexts, which can be:

• Documents
• Workers (regular web workers, shared workers and service workers) (As of today, shared workers and service workers are only supported in the browser toolbox)
• Processes (only for the browser toolbox)
• Extensions (only from the browser toolbox, or per-extension dedicated toolbox)

Each instance of these contexts are called "target" in DevToools.

ochameau

A few gifs about Fission support in DevTools

ochameau

Fission

Fission and BrowsingContexts

What's that all about?

Here is what was happening before fission. When navigating between two WebSites, you were staying in the same content process:

 The current tab's content process                                                        

ochameau

commit 937187b5f15df622f08230e52e52c1d2a040e480
Author: Alexandre Poirot <[email protected]>
Date:   Thu May 10 10:28:23 2018 -0700

    oop pipeline
    
    MozReview-Commit-ID: 4bUO2sK7Guf

diff --git a/devtools/client/framework/target-from-url.js b/devtools/client/framework/target-from-url.js
index 5dcbff79f907..2f4c35fec0ec 100644

ochameau

DOM.getBoxModel (bug 1545726, patch, missing test)
DOM.getContentQuads [Experimental] (bug 1543151, patch, missing test)
DOM.setFileInputFiles (no bug)
Emulation.setDeviceMetricsOverride (bug 1544417, patch, missing test)
Emulation.setTouchEmulationEnabled (mocked, do nothing)
Input.dispatchKeyEvent (bug 1543142, patch, missing test, will need followups)
Input.dispatchMouseEvent (bug 1543185, patch, missing test, may need followups)
Inspector.detached (not sure it is needed)
Log.enable (partial implementation)
Log.entryAdded (partial implementation)

ochameau

1557849967292	[email protected]	WARN	Loading extension '[email protected]': Reading manifest: Invalid host permission: resource://pdf.js/
1557849967292	[email protected]	WARN	Loading extension '[email protected]': Reading manifest: Invalid host permission: about:reader*
Juggler listening on ws://127.0.0.1:38421

(/home/alex/gutenberg/node_modules/puppeteer-firefox/.local-browser/firefox-linux-2f959d575a3d61f5dda12e4e2dca1f46a92ab569/firefox/firefox:80886): dconf-WARNING **: 09:06:12.423: Unable to open /var/lib/snapd/desktop/dconf/profile/user: Permission denied
console.error: BroadcastService: 
  receivedBroadcastMessage: handler for
  remote-settings/monitor_changes
  threw error:
  Message: Error: Polling for changes failed: NetworkError when attempting to fetch resource..

ochameau

diff --git a/testing/talos/talos/tests/devtools/addon/content/tests/debugger/custom.js b/testing/talos/talos/tests/devtools/addon/content/tests/debugger/custom.js
index 320ce3b1768f..e6a848404bc4 100644
--- a/testing/talos/talos/tests/devtools/addon/content/tests/debugger/custom.js
+++ b/testing/talos/talos/tests/devtools/addon/content/tests/debugger/custom.js
@@ -96,14 +96,33 @@ async function stepDebuggerAndLog(tab, toolbox, testFunction) {
   }
 }
 
+function screenshot(win) {
+  const canvas = win.document.createElementNS(

ochameau

RemoteAgent
 => TabObserver()
    emits:
      - open   => Targets.connect(tab.linkedBrowser)
      - close  => Targets.disconnect(tab.linkedBrowser)
 => HttpServer()
 Handlers:
 => TargetListHandler(Targets)
 => ProtocolHandler(Targets)
 => VersionHandler(Targets)