update_engine: Update libchrome APIs to r405848

The new libchrome has been ported from Chromium and some APIs have
changed. Make necessary changes at call sites.

Notable changes from libchrome:
- base::Bind() now explicitly disallows captures in lambdas (which was
  never allowed in the style guide), so lambdas should now be written in
  a way that take the captures as parameters.

Bug: 29104761
Test: All tests in update_engine_unittest pass on dragonboard-eng build
Change-Id: Iec04c126630fd876114076e3cb10cf917c8817b0
diff --git a/payload_consumer/download_action_unittest.cc b/payload_consumer/download_action_unittest.cc
index 4ffd35c..5e9ef5c 100644
--- a/payload_consumer/download_action_unittest.cc
+++ b/payload_consumer/download_action_unittest.cc
@@ -395,8 +395,11 @@
   processor.EnqueueAction(&download_action);
   processor.EnqueueAction(&test_action);
 
-  loop.PostTask(FROM_HERE,
-                base::Bind([&processor] { processor.StartProcessing(); }));
+  loop.PostTask(
+      FROM_HERE,
+      base::Bind(
+          [](ActionProcessor* processor) { processor->StartProcessing(); },
+          base::Unretained(&processor)));
   loop.Run();
   EXPECT_FALSE(loop.PendingTasks());