Expose global state variables for sampling tracing to WebKit

webkit/glue/webkitplatformsupport_impl.h

 // 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.
 
 #ifndef WEBKIT_PLATFORM_SUPPORT_IMPL_H_
 #define WEBKIT_PLATFORM_SUPPORT_IMPL_H_
 
 #include "base/compiler_specific.h"
+#include "base/debug/trace_event.h"
 #include "base/platform_file.h"
 #include "base/threading/thread_local_storage.h"
 #include "base/timer.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/Platform.h"
 #include "ui/base/layout.h"
 #include "webkit/glue/resource_loader_bridge.h"
 #include "webkit/glue/webkit_glue_export.h"
 
 #if defined(USE_DEFAULT_RENDER_THEME)
 #include "webkit/glue/webthemeengine_impl_default.h"
@@ skipping 62 matching lines @@
   virtual WebKit::WebString userAgent(const WebKit::WebURL& url);
   virtual void getPluginList(bool refresh, WebKit::WebPluginListBuilder*);
   virtual void decrementStatsCounter(const char* name);
   virtual void incrementStatsCounter(const char* name);
   virtual void histogramCustomCounts(
     const char* name, int sample, int min, int max, int bucket_count);
   virtual void histogramEnumeration(
     const char* name, int sample, int boundary_value);
   virtual const unsigned char* getTraceCategoryEnabledFlag(
       const char* category_name);
+  virtual TRACE_EVENT_API_ATOMIC_WORD* getTraceSamplingState(
+      const unsigned thread_bucket);
   virtual void addTraceEvent(
       char phase,
       const unsigned char* category_enabled,
       const char* name,
       unsigned long long id,
       int num_args,
       const char** arg_names,
       const unsigned char* arg_types,
       const unsigned long long* arg_values,
       unsigned char flags);
@@ skipping 82 matching lines @@
   int shared_timer_suspended_;  // counter
   WebThemeEngineImpl theme_engine_;
   base::ThreadLocalStorage::Slot current_thread_slot_;
   scoped_ptr<webkit::WebCompositorSupportImpl> compositor_support_;
   scoped_ptr<FlingCurveConfiguration> fling_curve_configuration_;
 };
 
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_PLATFORM_SUPPORT_IMPL_H_