Set pid on the PlasmaWindow based on the client connection.

Summary: Depends on D5747.

Test Plan:

Reviewers: #plasma,sebas,graesslin

Subscribers: plasma-devel

abstract_client.cpp

@@ -704,6 +704,7 @@ void AbstractClient::setupWindowManagementInterface()
     };
     updateAppId();
     w->setSkipTaskbar(skipTaskbar());
+    w->setPid(pid());
     w->setShadeable(isShadeable());
     w->setShaded(isShade());
     w->setResizable(isResizable());

shell_client.cpp

@@ -981,6 +981,11 @@ void ShellClient::updateInternalWindowGeometry()
                         m_internalWindow->geometry().size() + QSize(borderLeft() + borderRight(), borderTop() + borderBottom())));
 }
 
+pid_t ShellClient::pid() const
+{
+    return surface()->client()->processId();
+}
+
 bool ShellClient::isInternal() const
 {
     return m_internal;

shell_client.h

@@ -108,6 +108,15 @@ public:
     quint32 windowId() const override {
         return m_windowId;
     }
+
+    /**
+     * The process for this client.
+     * Note that processes started by kwin will share its process id.
+     * @since 5.11
+     * @returns the process if for this client.
+     **/
+    pid_t pid() const override;
+
     bool isInternal() const;
     bool isLockScreen() const override;
     bool isInputMethod() const override;

toplevel.h

@@ -289,7 +289,7 @@ public:
     QByteArray wmClientMachine(bool use_localhost) const;
     const ClientMachine *clientMachine() const;
     Window wmClientLeader() const;
-    pid_t pid() const;
+    virtual pid_t pid() const;
     static bool resourceMatch(const Toplevel* c1, const Toplevel* c2);
 
     bool readyForPainting() const; // true if the window has been already painted its contents