SyzyASAN: Export experiment state to finch synthetic field trials.

chrome/browser/chrome_browser_main.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chrome_browser_main.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
@@ skipping 1206 matching lines @@
 #endif  // BUILDFLAG(ANDROID_JAVA_UI)
 
   LaunchDevToolsHandlerIfNeeded(parsed_command_line());
   if (parsed_command_line().HasSwitch(::switches::kAutoOpenDevToolsForTabs))
     g_browser_process->CreateDevToolsAutoOpener();
 
   for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
     chrome_extra_parts_[i]->PostProfileInit();
 }
 
+namespace {
+
+#if defined(SYZYASAN)
+void WINAPI SyzyASANExperimentCallback(const char* name, const char* group) {
+  ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(name, status);

[Alexei Svitkine (slow), 2016/05/04 15:01:45]

Does this compile? I believe you need to add a friend declaration to
ChromeMetricsServiceAccessor - which is the mechanism we use to ensure all the
users of this API have been reviewed by us.

[Sigurður Ásgeirsson, 2016/05/04 15:56:10]

Done.

+}
+
+void SetupSyzyASAN() {
+  typedef VOID(WINAPI* SyzyASANExperimentCallbackFn(const char* name,
+                                                    const char* group));
+  typedef VOID(WINAPI* SyzyASANEnumFeaturesFn)(SyzyASANExperimentCallbackFn);
+  HMODULE syzyasan_handle = ::GetModuleHandle(L"syzyasan_rtl.dll");
+  if (!syzyasan_handle)
+    return;
+
+  // Export the SyzyASAN experiments as synthetic field trials.
+  SyzyASANEnumFeaturesFn syzyasan_enum_features =
+      reinterpret_cast<SyzyASANEnumFeaturesFn>(
+            ::GetProcAddress("asan_EnumFeatures"));
+  if (syzyasan_enum_features) {
+    syzyasan_enum_features(&SyzyASANExperimentCallback);
+  }
+
+  // Enable the deferred free mechanism in the syzyasan module, which helps the
+  // performance by deferring some work on the critical path to a background
+  // thread.
+  if (base::FeatureList::IsEnabled(features::kSyzyasanDeferredFree)) {
+    typedef VOID(WINAPI * SyzyasanEnableDeferredFreeThreadFunc)(VOID);
+    bool success = false;
+    SyzyasanEnableDeferredFreeThreadFunc syzyasan_enable_deferred_free =
+        reinterpret_cast<SyzyasanEnableDeferredFreeThreadFunc>(
+            ::GetProcAddress(syzyasan_handle,
+                             "asan_EnableDeferredFreeThread"));
+    if (syzyasan_enable_deferred_free) {
+      syzyasan_enable_deferred_free();
+      success = true;
+    }
+    UMA_HISTOGRAM_BOOLEAN("Syzyasan.DeferredFreeWasEnabled", success);
+  }
+}
+#endif  // SYZYASAN
+
+}  // namespace
+
 void ChromeBrowserMainParts::PreBrowserStart() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::PreBrowserStart");
   for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
     chrome_extra_parts_[i]->PreBrowserStart();
 
   three_d_observer_.reset(new ThreeDAPIObserver());
 
 #if defined(SYZYASAN)
-  // Enable the deferred free mechanism in the syzyasan module, which helps the
-  // performance by deferring some work on the critical path to a background
-  // thread.
-  if (base::FeatureList::IsEnabled(features::kSyzyasanDeferredFree)) {
-    typedef VOID(WINAPI * SyzyasanEnableDeferredFreeThreadFunc)(VOID);
-    HMODULE syzyasan_handle = ::GetModuleHandle(L"syzyasan_rtl.dll");
-    bool success = false;
-    if (syzyasan_handle) {
-      SyzyasanEnableDeferredFreeThreadFunc syzyasan_enable_deferred_free =
-          reinterpret_cast<SyzyasanEnableDeferredFreeThreadFunc>(
-              ::GetProcAddress(syzyasan_handle,
-                               "asan_EnableDeferredFreeThread"));
-      if (syzyasan_enable_deferred_free) {
-        syzyasan_enable_deferred_free();
-        success = true;
-      }
-    }
-    UMA_HISTOGRAM_BOOLEAN("Syzyasan.DeferredFreeWasEnabled", success);
-  }
+  SetupSyzyASAN();
 #endif
 
 // Start the tab manager here so that we give the most amount of time for the
 // other services to start up before we start adjusting the oom priority.
 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
   g_browser_process->GetTabManager()->Start();
 #endif
 }
 
 void ChromeBrowserMainParts::PostBrowserStart() {
@@ skipping 688 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }