The ScrollingBehavior passed around extensively in TabParent/TabChild is
entirely redundant now that the layers.async-pan-zoom.enabled pref definitively
controls whether or not APZ is enabled. All the code related to ScrollingBehavior
can be removed.
This change reworks how TabContext stores its data. Before, it stored
an app-id and translated that into an app; now we do the reverse. This
lets us guarantee that HasOwnApp() is true iff GetOwnApp() is non-null.
We added a new class, MaybeInvalidTabContext to assist with converting
from an IPCTabContext to a TabContext. This allows us to ensure that a
TabContext object is never invalid.
This change reworks how TabContext stores its data. Before, it stored
an app-id and translated that into an app; now we do the reverse. This
lets us guarantee that HasOwnApp() is true iff GetOwnApp() is non-null.
We added a new class, MaybeInvalidTabContext to assist with converting
from an IPCTabContext to a TabContext. This allows us to ensure that a
TabContext object is never invalid.
--HG--
extra : rebase_source : d43e858739a342ab420122a90336bfd585be268a
This is a rollup of the following patches
Bug 811315, part 0.9: Fix pre-existing race condition that allows dying ContentParents to accidentally try to load new TabParents. r=jlebar
Bug 811315, part 0.91: Fix another pre-existing race condition where FirstIdle might run after ContentChild::ActorDestroy(). r=jlebar
Bug 811315, part 1: Make "browser" process limit infinite and unload the processes when all tabs are closed. Firefox with process-per-tab! r=jlebar
Bug 811315, part 2: Pass scrolling-behavior hint down into TabParent instead of inferring it from app/browser. r=jlebar
Bug 811315, part 3: Add a mozasyncpanzoom attribute for iframes and honor it when constructing a remote frame. r=jlebar sr=roc
The main bug fixed here is that in half of our interfaces, we use "is browser frame/element" to mean "browser or app", and in the other half, we use it to mean "is browser not app".
There's a related, functional bug also fixed here, which is that a browser process doesn't inherit its parent's app-id. This causes problems e.g. for IndexedDB: If a browser inside an app uses IndexedDB, the DB should have the app's app-id.
I also modified Tab{Parent,Child} and nsFrameLoader to call "app" "ownOrContainingApp", to emphasize that we might have inherited the app from a parent process. I left nsIDocShell::appId alone, because changing that would have necessitated changing nsILoadGroup and therefore a /lot/ of users in Necko; it's also not clear it would have clarified anything in those cases.
The main bug fixed here is that in half of our interfaces, we use "is browser frame/element" to mean "browser or app", and in the other half, we use it to mean "is browser not app".
There's a related, functional bug also fixed here, which is that a browser process doesn't inherit its parent's app-id. This causes problems e.g. for IndexedDB: If a browser inside an app uses IndexedDB, the DB should have the app's app-id.
I also modified Tab{Parent,Child} and nsFrameLoader to call "app" "ownOrContainingApp", to emphasize that we might have inherited the app from a parent process. I left nsIDocShell::appId alone, because changing that would have necessitated changing nsILoadGroup and therefore a /lot/ of users in Necko; it's also not clear it would have clarified anything in those cases.
