Mandoline: Fix PackageManager initialization

mojo/runner/context.cc

Index: mojo/runner/context.cc
diff --git a/mojo/runner/context.cc b/mojo/runner/context.cc
index a1e59899e80d048d3e60bf35fe1d99fba794857f..b6d78e333d17a9def89f69a54854344420758ecb 100644
--- a/mojo/runner/context.cc
+++ b/mojo/runner/context.cc
@@ -162,7 +162,9 @@ class TracingServiceProvider : public ServiceProvider {
 }  // namespace
 
 Context::Context(const base::FilePath& shell_file_root)
-    : shell_file_root_(shell_file_root), main_entry_time_(base::Time::Now()) {}
+    : shell_file_root_(shell_file_root),
+      package_manager_(nullptr),
+      main_entry_time_(base::Time::Now()) {}
 
 Context::~Context() {
   DCHECK(!base::MessageLoop::current());