platform2: Fix issues with new version of libchrome

libchrome r334380 has the following breaking changes that need to be fixed:
- base::JSONWriter::Write() and base::JSONWriter::WriteWithOptions() take
  "const base::Value&" instead of "const base::Value*"
- base::JSONReader::Read() and base::JSONReader::ReadAndReturnError()
  return a scoped_ptr<base::Value> instead of base::Value*
- base/safe_strerror_posix.h is moved to base/posix/safe_strerror.h
- safe_strerror() is now in "base" namespace
- StartsWithASCII(), EndsWith(), StringToUpperASCII(), LowerCaseEqualsASCII()
  are now in "base" namespace
- ObserverList<T> is now in "base" namespace
- base::PrintTo(base::FilePath) used in gtest is now moved to libchrome-test
  library and as such, unit test runners need to link to this library now.
- crypto::RSAPrivateKey::CreateSensitive() is now removed from //crypto, so
  some of tests in chromeos-login that used that function had to be changed
  to use crypto::GenerateRSAKeyPairNSS() directly.
- UnixDomanSocket class is now in "base" namespace
- Pickle class is now in "base" namespace

BUG=chromium:496469
TEST=`./build_packages`
CQ-DEPEND=CL:277662

Change-Id: I36e5fbf2e36a92068873ffbd44020c862a3ed9e3
Reviewed-on: https://chromium-review.googlesource.com/277671
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Trybot-Ready: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/payload_state.cc b/payload_state.cc
index 5ed219e..ed7b775 100644
--- a/payload_state.cc
+++ b/payload_state.cc
@@ -527,9 +527,9 @@
     current_download_source_ = kDownloadSourceHttpPeer;
   } else if (GetUrlIndex() < candidate_urls_.size())  {
     string current_url = candidate_urls_[GetUrlIndex()];
-    if (StartsWithASCII(current_url, "https://", false))
+    if (base::StartsWithASCII(current_url, "https://", false))
       current_download_source_ = kDownloadSourceHttpsServer;
-    else if (StartsWithASCII(current_url, "http://", false))
+    else if (base::StartsWithASCII(current_url, "http://", false))
       current_download_source_ = kDownloadSourceHttpServer;
   }
 
@@ -1333,8 +1333,8 @@
   candidate_urls_.clear();
   for (size_t i = 0; i < response_.payload_urls.size(); i++) {
     string candidate_url = response_.payload_urls[i];
-    if (StartsWithASCII(candidate_url, "http://", false) && !http_url_ok)
-        continue;
+    if (base::StartsWithASCII(candidate_url, "http://", false) && !http_url_ok)
+      continue;
     candidate_urls_.push_back(candidate_url);
     LOG(INFO) << "Candidate Url" << (candidate_urls_.size() - 1)
               << ": " << candidate_url;