Slow Reports - Add message filter to trigger background traces from child processes.

content/browser/tracing/background_tracing_manager_impl.h

Index: content/browser/tracing/background_tracing_manager_impl.h
diff --git a/content/browser/tracing/background_tracing_manager_impl.h b/content/browser/tracing/background_tracing_manager_impl.h
index 6ad99bbe59f743dd15e58d754da7ddb871c0acb8..952496d1cedafcbd691b5db8cc18cd06a32cf77e 100644
--- a/content/browser/tracing/background_tracing_manager_impl.h
+++ b/content/browser/tracing/background_tracing_manager_impl.h
@@ -16,6 +16,7 @@
 
 namespace content {
 
+class TraceMessageFilter;
 class TracingDelegate;
 
 class BackgroundTracingManagerImpl : public content::BackgroundTracingManager {
@@ -37,10 +38,16 @@ class BackgroundTracingManagerImpl : public content::BackgroundTracingManager {
   void FireTimerForTesting() override;
   bool HasActiveScenarioForTesting() override;
 
+  void AddFilter(scoped_refptr<TraceMessageFilter> filter);
+  void RemoveFilter(scoped_refptr<TraceMessageFilter> filter);
+
+  void OnHistogramTrigger(const std::string& histogram_name) override;
+
  private:
   BackgroundTracingManagerImpl();
   ~BackgroundTracingManagerImpl() override;
 
+  void CreateDelegate();
   void EnableRecording(std::string, base::trace_event::TraceRecordMode);
   void EnableRecordingIfConfigNeedsIt();
   void OnFinalizeStarted(base::RefCountedString*);
@@ -53,9 +60,12 @@ class BackgroundTracingManagerImpl : public content::BackgroundTracingManager {
 
   void SetupUMACallbacks(SetupUMACallMode mode);
 
-  void OnHistogramChanged(const std::string& histogram_name,
-                          base::Histogram::Sample reference_value,
-                          base::Histogram::Sample actual_value);
+  void OnHistogramChangedCallback(const std::string& histogram_name,
+                                  base::Histogram::Sample reference_value,
+                                  base::Histogram::Sample actual_value);
+  void SetupFiltersFromConfig(SetupUMACallMode mode);
+  void SetupFilterFromConfig(scoped_refptr<TraceMessageFilter> filter,
+                             SetupUMACallMode mode);
 
   scoped_ptr<base::DictionaryValue> GenerateMetadataDict() const;
 
@@ -85,6 +95,9 @@ class BackgroundTracingManagerImpl : public content::BackgroundTracingManager {
     StartedFinalizingCallback callback_;
   };
 
+  typedef std::set<scoped_refptr<TraceMessageFilter>> FilterSet;
+  FilterSet filters_;

[oystein (OOO til 10th of July), 2015/07/21 20:52:45]

Could we just use the list in TraceControllerImpl, instead of tracking this
separately?

[shatch, 2015/07/22 17:44:13]

Thought about this a bit more, didn't get any great ideas on a cleaner way. To
reuse the list in TraceControllerImpl, we need to expose both a GetFilters()
method as well as some way to get notified when a filter is added so that we can
send the appropriate IPC's to setup callbacks. Put up a version that does that,
tell me what you think.

+
   scoped_ptr<TracingDelegate> delegate_;
   scoped_ptr<content::BackgroundTracingConfig> config_;
   std::map<TriggerHandle, std::string> trigger_handles_;