[geary/wip/728002-webkit2: 67/105] Disable WebKit2 accelerated compositing.

[Michael Gratton <mjog src gnome org>]

commit 331963ce2699bed3a5bd4851b80b6365e222d60a
Author: Michael James Gratton <mike vee net>
Date:   Wed Nov 23 10:12:41 2016 +1100

    Disable WebKit2 accelerated compositing.

 src/client/application/main.vala |   16 ++++++++++++----
 1 files changed, 12 insertions(+), 4 deletions(-)
---
diff --git a/src/client/application/main.vala b/src/client/application/main.vala
index c14ae6a..f41d18e 100644
--- a/src/client/application/main.vala
+++ b/src/client/application/main.vala
@@ -19,15 +19,23 @@ int main(string[] args) {
 #if !DISABLE_POODLE
     Environment.set_variable("G_TLS_GNUTLS_PRIORITY", "NORMAL:%COMPAT:%LATEST_RECORD_VERSION:!VERS-SSL3.0", 
false);
 #endif
-    
+
+    // Disable WebKit2 accelerated compositing here while we can't
+    // depend on there being an API to do it. AC isn't appropriate
+    // since Geary is likely to be doing anything that requires
+    // acceleration, and it is costs a lot in terms of performance
+    // and memory:
+    // https://lists.webkit.org/pipermail/webkit-gtk/2016-November/002863.html
+    Environment.set_variable("WEBKIT_DISABLE_COMPOSITING_MODE", "1", true);
+
     GearyApplication app = new GearyApplication();
-    
+
     int ec = app.run(args);
-    
+
 #if REF_TRACKING
     Geary.BaseObject.dump_refs(stdout);
 #endif
-    
+
     return ec;
 }