diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2bce66796b..6319afeb0c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2009-12-02  Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+	* ada-lang.c (ada_value_assign): Use observer_notify_memory_changed.
+	* valops.c (value_assign): Likewise.
+	* defs.h (deprecated_memory_changed_hook): Remove.
+	* top.c (deprecated_memory_changed_hook): Likewise.
+	* interps.c (clear_interpreter_hooks): Adjust.	
+	
 2009-12-02  Tristan Gingold  <gingold@adacore.com>
 
 	* symfile.h (dwarf2_build_psymtabs): Remove mainline parameter in
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 9594d6d601..599b8d60a7 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -2289,9 +2289,8 @@ ada_value_assign (struct value *toval, struct value *fromval)
         move_bits (buffer, value_bitpos (toval),
 		   value_contents (fromval), 0, bits, 0);
       write_memory (to_addr, buffer, len);
-      if (deprecated_memory_changed_hook)
-	deprecated_memory_changed_hook (to_addr, len);
-      
+      observer_notify_memory_changed (to_addr, len, buffer);
+
       val = value_copy (toval);
       memcpy (value_contents_raw (val), value_contents (fromval),
               TYPE_LENGTH (type));
diff --git a/gdb/defs.h b/gdb/defs.h
index 83e73cda17..b944ffb4d8 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -1108,7 +1108,6 @@ extern void (*deprecated_readline_begin_hook) (char *, ...)
 extern char *(*deprecated_readline_hook) (char *);
 extern void (*deprecated_readline_end_hook) (void);
 extern void (*deprecated_register_changed_hook) (int regno);
-extern void (*deprecated_memory_changed_hook) (CORE_ADDR addr, int len);
 extern void (*deprecated_context_hook) (int);
 extern ptid_t (*deprecated_target_wait_hook) (ptid_t ptid,
 					      struct target_waitstatus *status,
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 090aa14573..73a640d104 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2009-12-02  Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+	* observer.texi: New memory_changed observer.
+
 2009-12-01  Tom Tromey  <tromey@redhat.com>
 
 	* gdb.texinfo (Reverse Execution): Fix typo.
diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index 0ea9397fa4..1f733749ed 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -206,6 +206,11 @@ the old value, and @var{new_ptid} specifies the new value.
 @deftypefun void inferior_exit (int @var{pid})
 Either @value{GDBN} detached from the inferior, or the inferior
 exited.  The argument @var{pid} identifies the inferior.
+@end deftypefun
+
+@deftypefun void memory_changed (CORE_ADDR @var{addr}, int @var{len}, const bfd_byte *@var{data})
+Bytes from @var{data} to @var{data} + @var{len} have been written
+to the current inferior at @var{addr}.
 @end deftypefun
 
  @deftypefun void test_notification (int @var{somearg})
diff --git a/gdb/interps.c b/gdb/interps.c
index da05ee26ed..483f42c9a8 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -343,7 +343,6 @@ clear_interpreter_hooks (void)
   deprecated_readline_hook = 0;
   deprecated_readline_end_hook = 0;
   deprecated_register_changed_hook = 0;
-  deprecated_memory_changed_hook = 0;
   deprecated_context_hook = 0;
   deprecated_target_wait_hook = 0;
   deprecated_call_command_hook = 0;
diff --git a/gdb/top.c b/gdb/top.c
index b6701b6ab8..69a11ad5be 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -259,9 +259,6 @@ void (*deprecated_interactive_hook) (void);
    that several registers have changed (see value_assign). */
 void (*deprecated_register_changed_hook) (int regno);
 
-/* Tell the GUI someone changed LEN bytes of memory at ADDR */
-void (*deprecated_memory_changed_hook) (CORE_ADDR addr, int len);
-
 /* Called when going to wait for the target.  Usually allows the GUI to run
    while waiting for target events.  */
 
diff --git a/gdb/valops.c b/gdb/valops.c
index 2771688774..34619d34de 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -861,8 +861,8 @@ value_assign (struct value *toval, struct value *fromval)
 	  }
 
 	write_memory (changed_addr, dest_buffer, changed_len);
-	if (deprecated_memory_changed_hook)
-	  deprecated_memory_changed_hook (changed_addr, changed_len);
+	observer_notify_memory_changed (changed_addr, changed_len,
+					dest_buffer);
       }
       break;