crash-reporter: Capture and send recent update_engine logs when it crashes

user_collector.h

Index: user_collector.h
diff --git a/user_collector.h b/user_collector.h
index 109bf0c7205d9f5772557d82e981643242f74254..90bc578eec65249d5375f162f76833c91017f3a0 100644
--- a/user_collector.h
+++ b/user_collector.h
@@ -47,6 +47,11 @@ class UserCollector : public CrashCollector {
     core_pattern_file_ = pattern;
   }
 
+  // Set (override the default) core pipe limit file.
+  void set_core_pipe_limit_file(const std::string &path) {
+    core_pipe_limit_file_ = path;
+  }
+
  private:
   friend class UserCollectorTest;
   FRIEND_TEST(UserCollectorTest, CopyOffProcFilesBadPath);
@@ -107,6 +112,7 @@ class UserCollector : public CrashCollector {
 
   bool generate_diagnostics_;
   std::string core_pattern_file_;
+  std::string core_pipe_limit_file_;
   std::string our_path_;
   bool initialized_;