Support --trace-startup and task tracing

passing --trace-startup puts the tracing system into record mode immediately saving the result to chrometrace.log or a file specified by --trace-startup-file


BUG=None
TEST=start chrome with --trace-startup, wait 5 secs, see chrometrace.log in current dir. open it in chrome://tracing/


Review URL: http://codereview.chromium.org/7887013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@109281 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 15 insertions, 5 deletions

diff --git a/content/browser/trace_controller.h b/content/browser/trace_controller.h
index b14ec6a..1677056 100644
--- a/content/browser/trace_controller.h
+++ b/content/browser/trace_controller.h
@@ -13,6 +13,7 @@
 #include "base/memory/singleton.h"
 #include "content/common/content_export.h"
 
+class CommandLine;
 class TraceMessageFilter;
 
 // Objects interested in receiving trace data derive from TraceSubscriber.
@@ -28,8 +29,11 @@ class CONTENT_EXPORT TraceSubscriber {
   virtual void OnTraceDataCollected(const std::string& trace_fragment) = 0;
   // Called once after TraceController::GetKnownCategoriesAsync.
   virtual void OnKnownCategoriesCollected(
-      const std::set<std::string>& known_categories) {}
-  virtual void OnTraceBufferPercentFullReply(float percent_full) {}
+      const std::set<std::string>& known_categories);
+  virtual void OnTraceBufferPercentFullReply(float percent_full);
+
+ protected:
+  virtual ~TraceSubscriber();
 };
 
 // TraceController is used on the browser processes to enable/disable
@@ -40,6 +44,10 @@ class CONTENT_EXPORT TraceController {
  public:
   static TraceController* GetInstance();
 
+  // Called on the main thread of the browser process to initialize
+  // startup tracing.
+  void InitStartupTracing(const CommandLine& command_line);
+
   // Get set of known categories. This can change as new code paths are reached.
   // If true is returned, subscriber->OnKnownCategoriesCollected will be called
   // when once the categories are retrieved from child processes.
@@ -134,14 +142,16 @@ class CONTENT_EXPORT TraceController {
         pending_bpf_ack_count_ == 0;
   }
 
-  bool can_begin_tracing() const { return !is_tracing_; }
+  bool can_begin_tracing(TraceSubscriber* subscriber) const {
+    return !is_tracing_ &&
+        (subscriber_ == NULL || subscriber == subscriber_);
+  }
 
   // Methods for use by TraceMessageFilter.
 
-  // Passing as scoped_refptr so that the method can be run asynchronously as
-  // a task safely (otherwise the TraceMessageFilter could be destructed).
   void AddFilter(TraceMessageFilter* filter);
   void RemoveFilter(TraceMessageFilter* filter);
+  void OnTracingBegan(TraceSubscriber* subscriber);
   void OnEndTracingAck(const std::vector<std::string>& known_categories);
   void OnTraceDataCollected(
       const scoped_refptr<base::debug::TraceLog::RefCountedString>&