Adding in-process crash dumping library and crash uploader

src/platform/crash/user_collector.cc

Index: src/platform/crash/user_collector.cc
diff --git a/src/platform/crash/user_collector.cc b/src/platform/crash/user_collector.cc
index 9c6fd0bc039bd25f827b40092e269b7e608737c3..7033ada1133c586c9b5f30988bc542a8bd4cca05 100644
--- a/src/platform/crash/user_collector.cc
+++ b/src/platform/crash/user_collector.cc
@@ -57,7 +57,8 @@ bool UserCollector::SetUpInternal(bool enabled) {
   std::string pattern = GetPattern(enabled);
   if (file_util::WriteFile(FilePath(core_pattern_file_),
                            pattern.c_str(),
-                           pattern.length()) != pattern.length()) {
+                           pattern.length()) !=
+      static_cast<int>(pattern.length())) {
     logger_->LogError("Unable to write %s", core_pattern_file_.c_str());
     return false;
   }