Enable chromium trace when atrace is started.

The X event change (https://codereview.chromium.org/23799005/) depends
on the TraceBuffer to handle X events, so we need to enable chromium
trace when using systrace on Android to trace WebView or Chrome.

Part of this change is separated from https://codereview.chromium.org/26675003/
which is not ready to submit before WebView and Android are ready for
combined trace.

BUG=trace-viewer:142

Review URL: https://codereview.chromium.org/26848006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228813 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 33 insertions, 65 deletions

diff --git a/base/debug/trace_event_android.cc b/base/debug/trace_event_android.cc
index 05f8dcf..d4b4770 100644
--- a/base/debug/trace_event_android.cc
+++ b/base/debug/trace_event_android.cc
@@ -64,25 +64,38 @@ void WriteEvent(
 namespace base {
 namespace debug {
 
+// These functions support Android systrace.py when 'webview' category is
+// traced. With the new adb_profile_chrome, we may have two phases:
+// - before WebView is ready for combined tracing, we can use adb_profile_chrome
+//   to trace android categories other than 'webview' and chromium categories.
+//   In this way we can avoid the conflict between StartATrace/StopATrace and
+//   the intents.
+// - TODO(wangxianzhu): after WebView is ready for combined tracing, remove
+//   StartATrace, StopATrace and SendToATrace, and perhaps send Java traces
+//   directly to atrace in trace_event_binding.cc.
+
 void TraceLog::StartATrace() {
-  AutoLock lock(lock_);
+  if (g_atrace_fd != -1)
+    return;
+
+  g_atrace_fd = open(kATraceMarkerFile, O_WRONLY);
   if (g_atrace_fd == -1) {
-    g_atrace_fd = open(kATraceMarkerFile, O_WRONLY);
-    if (g_atrace_fd == -1) {
-      LOG(WARNING) << "Couldn't open " << kATraceMarkerFile;
-    } else {
-      UpdateCategoryGroupEnabledFlags();
-    }
+    PLOG(WARNING) << "Couldn't open " << kATraceMarkerFile;
+    return;
   }
+  SetEnabled(CategoryFilter(CategoryFilter::kDefaultCategoryFilterString),
+             RECORD_CONTINUOUSLY);
 }
 
 void TraceLog::StopATrace() {
-  AutoLock lock(lock_);
-  if (g_atrace_fd != -1) {
-    close(g_atrace_fd);
-    g_atrace_fd = -1;
-    UpdateCategoryGroupEnabledFlags();
-  }
+  if (g_atrace_fd == -1)
+    return;
+
+  close(g_atrace_fd);
+  g_atrace_fd = -1;
+  SetDisabled();
+  // Delete the buffered trace events as they have been sent to atrace.
+  Flush(OutputCallback());
 }
 
 void TraceLog::SendToATrace(
@@ -141,20 +154,6 @@ void TraceLog::SendToATrace(
   }
 }
 
-// Must be called with lock_ locked.
-void TraceLog::ApplyATraceEnabledFlag(unsigned char* category_group_enabled) {
-  if (g_atrace_fd == -1)
-    return;
-
-  // Don't enable disabled-by-default categories for atrace.
-  const char* category_group = GetCategoryGroupName(category_group_enabled);
-  if (strncmp(category_group, TRACE_DISABLED_BY_DEFAULT(""),
-              strlen(TRACE_DISABLED_BY_DEFAULT(""))) == 0)
-    return;
-
-  *category_group_enabled |= ATRACE_ENABLED;
-}
-
 void TraceLog::AddClockSyncMetadataEvent() {
   int atrace_fd = open(kATraceMarkerFile, O_WRONLY | O_APPEND);
   if (atrace_fd == -1) {
diff --git a/base/debug/trace_event_impl.cc b/base/debug/trace_event_impl.cc
index e606717..6a0bff9 100644
--- a/base/debug/trace_event_impl.cc
+++ b/base/debug/trace_event_impl.cc
@@ -1212,9 +1212,10 @@ const char* TraceLog::GetCategoryGroupName(
 }
 
 void TraceLog::UpdateCategoryGroupEnabledFlag(int category_index) {
-  bool is_enabled = enable_count_ && category_filter_.IsCategoryGroupEnabled(
-      g_category_groups[category_index]);
-  SetCategoryGroupEnabled(category_index, is_enabled);
+  g_category_group_enabled[category_index] =
+      enable_count_ &&
+      category_filter_.IsCategoryGroupEnabled(
+          g_category_groups[category_index]);
 }
 
 void TraceLog::UpdateCategoryGroupEnabledFlags() {
@@ -1222,22 +1223,6 @@ void TraceLog::UpdateCategoryGroupEnabledFlags() {
     UpdateCategoryGroupEnabledFlag(i);
 }
 
-void TraceLog::SetCategoryGroupEnabled(int category_index, bool is_enabled) {
-  g_category_group_enabled[category_index] =
-      is_enabled ? CATEGORY_GROUP_ENABLED : 0;
-
-#if defined(OS_ANDROID)
-  ApplyATraceEnabledFlag(&g_category_group_enabled[category_index]);
-#endif
-}
-
-bool TraceLog::IsCategoryGroupEnabled(
-    const unsigned char* category_group_enabled) {
-  // On Android, ATrace and normal trace can be enabled independently.
-  // This function checks if the normal trace is enabled.
-  return *category_group_enabled & CATEGORY_GROUP_ENABLED;
-}
-
 const unsigned char* TraceLog::GetCategoryGroupEnabledInternal(
     const char* category_group) {
   DCHECK(!strchr(category_group, '"')) <<
@@ -1700,6 +1685,9 @@ void TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     const unsigned long long* arg_values,
     const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
     unsigned char flags) {
+  if (!*category_group_enabled)
+    return;
+
   DCHECK(name);
 
   if (flags & TRACE_EVENT_FLAG_MANGLE_ID)
@@ -1711,9 +1699,6 @@ void TraceLog::AddTraceEventWithThreadIdAndTimestamp(
                flags);
 #endif
 
-  if (!IsCategoryGroupEnabled(category_group_enabled))
-    return;
-
   TimeTicks now = timestamp - time_offset_;
   TimeTicks thread_now = ThreadNow();
 
diff --git a/base/debug/trace_event_impl.h b/base/debug/trace_event_impl.h
index b101bc8..75fa5aa 100644
--- a/base/debug/trace_event_impl.h
+++ b/base/debug/trace_event_impl.h
@@ -573,21 +573,6 @@ class BASE_EXPORT TraceLog {
   void UpdateCategoryGroupEnabledFlags();
   void UpdateCategoryGroupEnabledFlag(int category_index);
 
-  static void SetCategoryGroupEnabled(int category_index, bool enabled);
-  static bool IsCategoryGroupEnabled(
-      const unsigned char* category_group_enabled);
-
-  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
-  // value with zero or more of the following bits. Used in this class only.
-  // The TRACE_EVENT macros should only use the value as a bool.
-  enum CategoryGroupEnabledFlags {
-    // Normal enabled flag for category groups enabled with Enable().
-    CATEGORY_GROUP_ENABLED = 1 << 0,
-    // On Android if ATrace is enabled, all categories will have this bit.
-    // Not used on other platforms.
-    ATRACE_ENABLED = 1 << 1
-  };
-
   // Helper class for managing notification_thread_count_ and running
   // notification callbacks. This is very similar to a reader-writer lock, but
   // shares the lock with TraceLog and manages the notification flags.
@@ -630,7 +615,6 @@ class BASE_EXPORT TraceLog {
       const unsigned long long* arg_values,
       const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
       unsigned char flags);
-  static void ApplyATraceEnabledFlag(unsigned char* category_group_enabled);
 #endif
 
   TraceBuffer* trace_buffer() const { return logged_events_.get(); }