Expose memory allocator internal stats and properties.

base/allocator/allocator_extension.cc

Index: base/allocator/allocator_extension.cc
diff --git a/base/allocator/allocator_extension.cc b/base/allocator/allocator_extension.cc
index 7ae11da3e301121f328b265dac2bf489d3c5b52e..d19f51d78fc03ee55e967ae3ebd3a620ef8ace12 100644
--- a/base/allocator/allocator_extension.cc
+++ b/base/allocator/allocator_extension.cc
@@ -9,6 +9,14 @@
 namespace base {
 namespace allocator {
 
+bool GetProperty(const char* name, size_t* value) {
+  if (thunks::GetPropertyFunction* get_property_function =
+          base::allocator::thunks::GetGetPropertyFunction())

[jar (doing other things), 2012/08/11 03:39:46]

nit: No reason to put a declaration in an if.... so I'd suggest pulling it out
for easier reading.
That said, if you make the "if" line longer than one line, then you need
curlies.  

IMO, pull the declaration out, then if you want to be "fancy, " do something
closer to:

return (get_property_function != NULL) &&
    get_property_function(name, value);

Also... you might use:
property_getter()

as a shorter name for your variable |get_property_function|.

The current variable name seems to use a Hungarian notation, of putting the type
of "_function" on the end of the variable name.  I don't know if that is a
special common thing for thunks... but it just grows your variable names to be
bigger than needed IMO.

Given that the style guide specifically asks us to avoid Hungarian notations,
you might similarly change the other postfixed names in this file to something
like:

free_memory_releaser for release_free_memory_function
and
stats_getter for get_stats_function

[alexeif, 2012/08/11 11:19:55]

I don't like assignments inside 'if' either. I just tried to make it consistent
with the rest of the original code. You know I'm kinda guest in these files, so
I tried to keep the changes minimal.

Fixed it.

+    return get_property_function(name, value);
+  else

[jar (doing other things), 2012/08/11 03:39:46]

nit: no need for else... as you're returning.

[alexeif, 2012/08/11 11:19:55]

Done.

+    return false;
+}
+
 void GetStats(char* buffer, int buffer_length) {
   DCHECK_GT(buffer_length, 0);
   if (thunks::GetStatsFunction* get_stats_function =
@@ -24,6 +32,13 @@ void ReleaseFreeMemory() {
     release_free_memory_function();
 }
 
+void SetGetPropertyFunction(
+    thunks::GetPropertyFunction* get_property_function) {
+  DCHECK_EQ(base::allocator::thunks::GetGetPropertyFunction(),
+            reinterpret_cast<thunks::GetPropertyFunction*>(NULL));
+  base::allocator::thunks::SetGetPropertyFunction(get_property_function);
+}
+
 void SetGetStatsFunction(thunks::GetStatsFunction* get_stats_function) {
   DCHECK_EQ(base::allocator::thunks::GetGetStatsFunction(),
             reinterpret_cast<thunks::GetStatsFunction*>(NULL));