Ignore deactivate when no valid EGL display. Fixes #1435

Initialise NativeMapView's EGL variables before Map

Fix hang

Add check for double pause

Add test for double pause

test/miscellaneous/map_context.cpp

@@ -0,0 +1,22 @@
+#include "../fixtures/util.hpp"
+
+#include <mbgl/util/run_loop.hpp>
+#include <mbgl/map/map_data.hpp>
+#include <mbgl/map/map_context.hpp>
+#include <mbgl/platform/default/headless_view.hpp>
+#include <mbgl/platform/default/headless_display.hpp>
+#include <mbgl/storage/default_file_source.hpp>
+
+using namespace mbgl;
+
+TEST(MapContext, DoubleStyleLoad) {
+    util::RunLoop runLoop(uv_default_loop());
+    std::shared_ptr<HeadlessDisplay> display = std::make_shared<HeadlessDisplay>();
+    HeadlessView view(display, 512, 512, 1);
+    DefaultFileSource fileSource(nullptr);
+    MapData data(view, MapMode::Continuous);
+    MapContext context(uv_default_loop(), view, fileSource, data);
+
+    context.setStyleJSON("", "");
+    context.setStyleJSON("", "");
+}