Support command-line argument --force-webrtc-ip-handling-policy

This command-line argument makes it possibly to block exposure of
internal IP addresses when WebRTC access hasn't been granted, using
--force-webrtc-ip-handling-policy=default_public_interface_only

Task-number: QTBUG-57505
Change-Id: I0cddd1b20e0814811894204cb31e0c463a75f7be
Reviewed-by: Kai Koehne <kai.koehne@qt.io>

src/core/web_contents_adapter.cpp

@@ -73,6 +73,7 @@
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/favicon_status.h"
 #include "content/public/common/content_constants.h"
+#include "content/public/common/content_switches.h"
 #include <content/public/common/drop_data.h>
 #include "content/public/common/page_state.h"
 #include "content/public/common/page_zoom.h"
@@ -419,6 +420,11 @@ void WebContentsAdapter::initialize(WebContentsAdapterClient *adapterClient)
     rendererPrefs->caret_blink_interval = 0.5 * static_cast<double>(qtCursorFlashTime) / 1000;
     rendererPrefs->user_agent_override = d->browserContextAdapter->httpUserAgent().toStdString();
     rendererPrefs->accept_languages = d->browserContextAdapter->httpAcceptLanguageWithoutQualities().toStdString();
+#if defined(ENABLE_WEBRTC)
+    base::CommandLine* commandLine = base::CommandLine::ForCurrentProcess();
+    if (commandLine->HasSwitch(switches::kForceWebRtcIPHandlingPolicy))
+        rendererPrefs->webrtc_ip_handling_policy = commandLine->GetSwitchValueASCII(switches::kForceWebRtcIPHandlingPolicy);
+#endif
     d->webContents->GetRenderViewHost()->SyncRendererPrefs();
 
     // Create and attach observers to the WebContents.