[iOS][wk2] Ensure that layers are marked volatile before allowing the process to suspend

[Tim Horton]

WebKit tries to make layers volatile when unparented, but sometimes isn't given a chance to do so before the process gets suspended, so we end up with lots of non-volatile surfaces that should really be volatile.

<rdar://problem/17186342>

[Tim Horton]

Created attachment 233271 [details]
patch

[Simon Fraser (smfr)]

Comment on attachment 233271 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=233271&action=review

> Source/WebKit2/Shared/mac/RemoteLayerBackingStoreCollection.h:65
> +    bool markBackingStoreVolatileImmediately(RemoteLayerBackingStore&, unsigned volatilityMarkingFlags = 0);

enum for the set of flag mask please, not unsigned.

> Source/WebKit2/Shared/mac/RemoteLayerBackingStoreCollection.mm:160
> +    for (const auto& backingStore : m_unparentedBackingStore)

Blank line above please.

> Source/WebKit2/UIProcess/ios/ProcessThrottler.mm:109
> +    // If the process is currently waiting for the WebProcess to become suspendable but would become runnable,
> +    // let it know that it can cancel the suspension cleanup.

Hard to grok

[Tim Horton]

(In reply to comment #2)
> (From update of attachment 233271 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=233271&action=review
> 
> > Source/WebKit2/Shared/mac/RemoteLayerBackingStoreCollection.h:65
> > +    bool markBackingStoreVolatileImmediately(RemoteLayerBackingStore&, unsigned volatilityMarkingFlags = 0);
> 
> enum for the set of flag mask please, not unsigned.

To clarify, .smfr says to use a typedef of unsigned for the flag argument type.

[Tim Horton]

Created attachment 233277 [details]
with simon's changes

This patch will now sit here for a bit while I work on the final remaining piece in another bug.

[WebKit Commit Bot]

Attachment 233277 [details] did not pass style-queue:


ERROR: Source/WebKit2/Shared/mac/RemoteLayerBackingStoreCollection.h:66:  The parameter name "volatilityMarkingFlags" adds no information, so it should be removed.  [readability/parameter_name] [5]
Total errors found: 1 in 15 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Gavin Barraclough]

LGTM

[Tim Horton]

http://trac.webkit.org/changeset/170316