Rename setExtraHeader to setHttpHeader in QWebEngineUrlRequestInfo.

Also make a small update to the documentation of the method.

Change-Id: Ie19578ffccfd30c884cdfe882dffcdae6637e8e2
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

src/core/api/qwebengineurlrequestinfo.cpp

@@ -274,10 +274,10 @@ void QWebEngineUrlRequestInfo::block(bool shouldBlock)
 }
 
 /*!
-    Sets an extra request header for this request with \a name and \a value.
+    Sets the request header \a name to \a value for this request.
 */
 
-void QWebEngineUrlRequestInfo::setExtraHeader(const QByteArray &name, const QByteArray &value)
+void QWebEngineUrlRequestInfo::setHttpHeader(const QByteArray &name, const QByteArray &value)
 {
     Q_D(QWebEngineUrlRequestInfo);
     d->changed = true;

src/core/api/qwebengineurlrequestinfo.h

@@ -92,7 +92,7 @@ public:
 
     void block(bool shouldBlock);
     void redirect(const QUrl &url);
-    void setExtraHeader(const QByteArray &name, const QByteArray &value);
+    void setHttpHeader(const QByteArray &name, const QByteArray &value);
 
 private:
     friend class QtWebEngineCore::NetworkDelegateQt;