https://bugs.webkit.org/show_bug.cgi?id=49090
<rdar://problem/7834575>

Reviewed by Darin Adler.

* Platform/CoreIPC/Connection.cpp:
(CoreIPC::Connection::connectionDidClose):
Call Client::didCloseOnConnectionWorkQueue.

* Platform/CoreIPC/Connection.h:
(CoreIPC::Connection::Client::didCloseOnConnectionWorkQueue):
Add new client function. Will be called on the connection work queue when the connection is closed.

* Platform/WorkItem.h:
(FunctionWorkItem0::FunctionWorkItem0):
(FunctionWorkItem0::execute):
(WorkItem::create):
Add a new WorkItem subclass that will invoke a C function.

* Platform/WorkQueue.h:
* Platform/mac/WorkQueueMac.cpp:
(WorkQueue::scheduleWorkAfterDelay):
New function which will schedule the given work item to be executed in at least 'delay' seconds.

* Platform/qt/WorkQueueQt.cpp:
(WorkQueue::scheduleWorkAfterDelay):
Add empty stub.

* Platform/win/WorkQueueWin.cpp:
(WorkQueue::scheduleWorkAfterDelay):
Ditto.

* PluginProcess/PluginProcess.h:
Derive from ChildProcess.

* Shared/ChildProcess.cpp: Added.
(WebKit::ChildProcess::ChildProcess):
(WebKit::ChildProcess::~ChildProcess):
(WebKit::watchdogCallback):
Call _exit.

(WebKit::ChildProcess::didCloseOnConnectionWorkQueue):
When the connection is closed, schedule a work item to be run in 10 seconds. If the process hasn't
exited normally by then, we'll exit.

* Shared/ChildProcess.h:
Add new ChildProcess class which is a common base class of WebProcess and PluginProcess and which contains
the watchdog timer logic.

* WebKit2.pro:
* WebKit2.xcodeproj/project.pbxproj:
Add new files.

* WebProcess/WebProcess.h:
Derive from ChildProcess.

* win/WebKit2.vcproj:
Add new files.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@71456 268f45cc-cd09-0410-ab3c-d52691b4dbfc