[geary/wip/webkit-maintenance] Temporarily replace WebKitGTK process model API with env var

[Michael Gratton <mjog src gnome org>]

commit 1e7906308b63b539350b2c76b8918f996c7e2285
Author: Michael Gratton <mike vee net>
Date:   Sat Sep 7 10:46:41 2019 +1000

    Temporarily replace WebKitGTK process model API with env var
    
    WebKit.ProcessModel.SHARED_SECONDARY_PROCESS is deprecated in 2.25.92,
    the warning is breaking tests. That release included a new
    WEBKIT_USE_SINGLE_WEB_PROCESS env var as a workaround, so switch to
    use that for now.
    
    See #558

 src/client/application/main.vala           | 5 +++++
 src/client/components/client-web-view.vala | 3 ---
 2 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/src/client/application/main.vala b/src/client/application/main.vala
index 5f99d5bf..d45bacf2 100644
--- a/src/client/application/main.vala
+++ b/src/client/application/main.vala
@@ -20,6 +20,11 @@ int main(string[] args) {
     Environment.set_variable("G_TLS_GNUTLS_PRIORITY", "NORMAL:%COMPAT:!VERS-SSL3.0", false);
 #endif
 
+    // Temporary workaround for WebKitGTK deprecation of the
+    // shared-secondary process model. Pull this out in 3.36 when the
+    // proper fix lands. See GNOME/geary#558.
+    Environment.set_variable("WEBKIT_USE_SINGLE_WEB_PROCESS", "1", true);
+
     GearyApplication app = new GearyApplication();
 
     int ec = app.run(args);
diff --git a/src/client/components/client-web-view.vala b/src/client/components/client-web-view.vala
index ecb707ab..0505b9aa 100644
--- a/src/client/components/client-web-view.vala
+++ b/src/client/components/client-web-view.vala
@@ -76,9 +76,6 @@ public abstract class ClientWebView : WebKit.WebView, Geary.BaseInterface {
                                         File cache_dir) {
         WebsiteDataManager data_manager = new WebsiteDataManager(cache_dir.get_path());
         WebKit.WebContext context = new WebKit.WebContext.with_website_data_manager(data_manager);
-        // Use a shared process so we don't spawn N WebProcess instances
-        // when showing N messages in a conversation.
-        context.set_process_model(WebKit.ProcessModel.SHARED_SECONDARY_PROCESS);
         // Use the doc viewer model since each web view instance only
         // ever shows a single HTML document.
         context.set_cache_model(WebKit.CacheModel.DOCUMENT_VIEWER);