Enable memory profiler on Linux when TC_MALLOC is enabled.

Added a tc_malloc memory extension to get bytes allocated on
current thread (GetBytesAllocatedOnCurrentThread API call).

R=jam@chromium.org,jar@chromium.org
BUG=139667
TEST=test about:profiler after setting the env variable 
     CHROME_PROFILER_TIME=1. In about:profiler, it will
     show the memory allocated per thread. This change
     impacts linux only.

Review URL: https://chromiumcodereview.appspot.com/10820063

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150135 0039d316-1c4b-4281-b951-d872f2087c98

content/app/content_main_runner.cc

@@ -4,6 +4,8 @@
 
 #include "content/public/app/content_main_runner.h"
 
+#include <stdlib.h>
+
 #include "base/allocator/allocator_extension.h"
 #include "base/at_exit.h"
 #include "base/command_line.h"
@@ -17,6 +19,7 @@
 #include "base/metrics/stats_table.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
+#include "base/profiler/alternate_timer.h"
 #include "base/stringprintf.h"
 #include "base/string_number_conversions.h"
 #include "content/browser/browser_main.h"
@@ -450,6 +453,17 @@ static void ReleaseFreeMemoryThunk() {
     // On windows, we've already set these thunks up in _heap_init()
     base::allocator::SetGetStatsFunction(GetStatsThunk);
     base::allocator::SetReleaseFreeMemoryFunction(ReleaseFreeMemoryThunk);
+
+    // Provide optional hook for monitoring allocation quantities on a
+    // per-thread basis.  Only set the hook if the environment indicates this
+    // needs to be enabled.
+    const char* profiling = getenv(tracked_objects::kAlternateProfilerTime);
+    if (profiling &&
+        (atoi(profiling) == tracked_objects::TIME_SOURCE_TYPE_TCMALLOC)) {
+      tracked_objects::SetAlternateTimeSource(
+          MallocExtension::GetBytesAllocatedOnCurrentThread,
+          tracked_objects::TIME_SOURCE_TYPE_TCMALLOC);
+    }
 #endif
 
     // On Android,

third_party/tcmalloc/chromium/src/gperftools/malloc_extension.h

-// Copyright (c) 2005, Google Inc.
+// Copyright (c) 2012, Google Inc.
 // All rights reserved.
 // 
 // Redistribution and use in source and binary forms, with or without
@@ -307,6 +307,10 @@ class PERFTOOLS_DLL_DECL MallocExtension {
   // malloc implementation during initialization.
   static void Register(MallocExtension* implementation);
 
+  // On the current thread, return the total number of bytes allocated.
+  // (Currently only implemented in tcmalloc.)
+  static unsigned int GetBytesAllocatedOnCurrentThread();
+
   // Returns detailed information about malloc's freelists. For each list,
   // return a FreeListInfo:
   struct FreeListInfo {

third_party/tcmalloc/chromium/src/malloc_extension.cc

-// Copyright (c) 2005, Google Inc.
+// Copyright (c) 2012, Google Inc.
 // All rights reserved.
 // 
 // Redistribution and use in source and binary forms, with or without
@@ -50,6 +50,7 @@
 #include "gperftools/malloc_extension.h"
 #include "gperftools/malloc_extension_c.h"
 #include "maybe_threads.h"
+#include "thread_cache.h"
 
 using STL_NAMESPACE::string;
 using STL_NAMESPACE::vector;
@@ -220,6 +221,10 @@ void MallocExtension::Register(MallocExtension* implementation) {
   }
 }
 
+unsigned int MallocExtension::GetBytesAllocatedOnCurrentThread() {
+  return tcmalloc::ThreadCache::GetBytesAllocatedOnCurrentThread();
+}
+
 // -----------------------------------------------------------------------
 // Heap sampling support
 // -----------------------------------------------------------------------