Copying the following files AS-IS from google.glog r141:

base/third_party/symbolize/symbolize.h

Index: base/third_party/symbolize/symbolize.h
diff --git a/base/third_party/symbolize/symbolize.h b/base/third_party/symbolize/symbolize.h
index 441e5436962f7ddd091dd348809a1b9220187561..f617184249ce2f6334dce25c0a2a5cbc29b2c003 100644
--- a/base/third_party/symbolize/symbolize.h
+++ b/base/third_party/symbolize/symbolize.h
@@ -105,6 +105,10 @@ _END_GOOGLE_NAMESPACE_
 
 _START_GOOGLE_NAMESPACE_
 
+// Restrictions on the callbacks that follow:
+//  - The callbacks must not use heaps but only use stacks.
+//  - The callbacks must be async-signal-safe.
+
 // Installs a callback function, which will be called right before a symbol name
 // is printed. The callback is intended to be used for showing a file name and a
 // line number preceding a symbol name.
@@ -116,6 +120,24 @@ typedef int (*SymbolizeCallback)(int fd, void *pc, char *out, size_t out_size,
                                  uint64 relocation);
 void InstallSymbolizeCallback(SymbolizeCallback callback);
 
+// Installs a callback function, which will be called instead of
+// OpenObjectFileContainingPcAndGetStartAddress.  The callback is expected
+// to searches for the object file (from /proc/self/maps) that contains
+// the specified pc.  If found, sets |start_address| to the start address
+// of where this object file is mapped in memory, sets the module base
+// address into |base_address|, copies the object file name into
+// |out_file_name|, and attempts to open the object file.  If the object
+// file is opened successfully, returns the file descriptor.  Otherwise,
+// returns -1.  |out_file_name_size| is the size of the file name buffer
+// (including the null-terminator).
+typedef int (*SymbolizeOpenObjectFileCallback)(uint64_t pc,
+                                               uint64_t &start_address,
+                                               uint64_t &base_address,
+                                               char *out_file_name,
+                                               int out_file_name_size);
+void InstallSymbolizeOpenObjectFileCallback(
+    SymbolizeOpenObjectFileCallback callback);
+
 _END_GOOGLE_NAMESPACE_
 
 #endif