update_engine: changes for libchrome r680000 uprev

Changes applied include:
Replace arraysize by base::size.
Replace base::MessageLoop::current()->task_runner by
base::ThreadTaskRunnerHandle::Get, and
base::MessageLoopForIO::current by base::MessageLoopCurrent::IsSet.
Remove use of base::ContainsKey.
Replace base::Int{,64}ToString by base::NumberTostring.

The changes are all compatible with current libchrome r576279.

BUG=chromium:1054279
TEST=unittest

Change-Id: Ibb6027a5070e0e2d4554a6684350168542fedf5e
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2065691
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Tested-by: Qijiang Fan <fqj@google.com>
Commit-Queue: Qijiang Fan <fqj@google.com>
diff --git a/libcurl_http_fetcher.cc b/libcurl_http_fetcher.cc
index 4bea4ef..d317d48 100644
--- a/libcurl_http_fetcher.cc
+++ b/libcurl_http_fetcher.cc
@@ -80,7 +80,7 @@
 #endif  // __ANDROID__
   LibcurlHttpFetcher* fetcher = static_cast<LibcurlHttpFetcher*>(clientp);
   // Stop watching the socket before closing it.
-  for (size_t t = 0; t < arraysize(fetcher->fd_controller_maps_); ++t) {
+  for (size_t t = 0; t < base::size(fetcher->fd_controller_maps_); ++t) {
     fetcher->fd_controller_maps_[t].erase(item);
   }
 
@@ -676,7 +676,7 @@
 
   // We should iterate through all file descriptors up to libcurl's fd_max or
   // the highest one we're tracking, whichever is larger.
-  for (size_t t = 0; t < arraysize(fd_controller_maps_); ++t) {
+  for (size_t t = 0; t < base::size(fd_controller_maps_); ++t) {
     if (!fd_controller_maps_[t].empty())
       fd_max = max(fd_max, fd_controller_maps_[t].rbegin()->first);
   }
@@ -694,7 +694,7 @@
         is_exc || (FD_ISSET(fd, &fd_write) != 0)  // track 1 -- write
     };
 
-    for (size_t t = 0; t < arraysize(fd_controller_maps_); ++t) {
+    for (size_t t = 0; t < base::size(fd_controller_maps_); ++t) {
       bool tracked =
           fd_controller_maps_[t].find(fd) != fd_controller_maps_[t].end();
 
@@ -775,7 +775,7 @@
   MessageLoop::current()->CancelTask(timeout_id_);
   timeout_id_ = MessageLoop::kTaskIdNull;
 
-  for (size_t t = 0; t < arraysize(fd_controller_maps_); ++t) {
+  for (size_t t = 0; t < base::size(fd_controller_maps_); ++t) {
     fd_controller_maps_[t].clear();
   }