Add sandbox support for AsanCoverage.

content/zygote/zygote_linux.h

Index: content/zygote/zygote_linux.h
diff --git a/content/zygote/zygote_linux.h b/content/zygote/zygote_linux.h
index ef7e071c9f5b10be1ad6de5abb72ae28cc953d78..4e038f4f39a6d1cf12b53c897f822a4ba98471d6 100644
--- a/content/zygote/zygote_linux.h
+++ b/content/zygote/zygote_linux.h
@@ -28,7 +28,9 @@ class ZygoteForkDelegate;
 // runs it.
 class Zygote {
  public:
-  Zygote(int sandbox_flags, ScopedVector<ZygoteForkDelegate> helpers);
+  Zygote(int sandbox_flags, ScopedVector<ZygoteForkDelegate> helpers,
+         const std::vector<base::ProcessHandle>& extra_children,
+         const std::vector<int>& extra_fds);
   ~Zygote();
 
   bool ProcessRequests();
@@ -123,6 +125,15 @@ class Zygote {
 
   // Count of how many fork delegates for which we've invoked InitialUMA().
   size_t initial_uma_index_;
+
+  // This vector contains the PIDs of any child processes which have been
+  // created prior to the construction of the Zygote object, and must be reaped
+  // before the Zygote exits.

[jln (very slow on Chromium), 2014/05/27 23:15:00]

Let's add more documentation:

"The Zygote will perform a blocking wait on these children, so they must be
guaranteed to be exiting by the time the Zygote exits.".

[earthdok, 2014/05/28 16:44:51]

Done.

+  std::vector<base::ProcessHandle> extra_children_;
+
+  // This vector contains the FDs that must be closed before reaping the extra
+  // children.
+  std::vector<int> extra_fds_;
 };
 
 }  // namespace content