Make crash reporting client_id accessible through child_process_logging.

base/linux_util.h

Index: base/linux_util.h
diff --git a/base/linux_util.h b/base/linux_util.h
index 91cb1138e959698e5aa5bcc303cf76b20acf4dbd..0d2f20e70a4ebf6b7fb2fdea699dd6c3291ee921 100644
--- a/base/linux_util.h
+++ b/base/linux_util.h
@@ -15,10 +15,17 @@ namespace base {
 
 static const char kFindInodeSwitch[] = "--find-inode";
 
+// This is declared here so the crash reporter can access the memory directly
+// in compromised context without going through the standard library.
+extern char g_linux_distro[];
+
 // Get the Linux Distro if we can, or return "Unknown", similar to
 // GetWinVersion() in base/win_util.h.
 std::string GetLinuxDistro();
 
+// Set the Linux Distro string.
+void SetLinuxDistro(const std::string& distro);
+
 // Return the inode number for the UNIX domain socket |fd|.
 bool FileDescriptorGetInode(ino_t* inode_out, int fd);