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/update_attempter_android.cc b/update_attempter_android.cc
index 01eb320..d435b52 100644
--- a/update_attempter_android.cc
+++ b/update_attempter_android.cc
@@ -372,7 +372,9 @@
 void UpdateAttempterAndroid::ScheduleProcessingStart() {
   LOG(INFO) << "Scheduling an action processor start.";
   brillo::MessageLoop::current()->PostTask(
-      FROM_HERE, Bind([this] { this->processor_->StartProcessing(); }));
+      FROM_HERE,
+      Bind([](ActionProcessor* processor) { processor->StartProcessing(); },
+           base::Unretained(processor_.get())));
 }
 
 void UpdateAttempterAndroid::TerminateUpdateAndNotify(ErrorCode error_code) {