2 files changed, 9 insertions, 6 deletions
diff --git a/tools/trace/SkEventTracingPriv.cpp b/tools/trace/SkEventTracingPriv.cpp
index 783cfeaa32..42d992cb13 100644
--- a/tools/trace/SkEventTracingPriv.cpp
+++ b/tools/trace/SkEventTracingPriv.cpp
@@ -22,12 +22,14 @@ DEFINE_string(trace, "",
               "               trace events to specified file as JSON, for viewing\n"
               "               with chrome://tracing");
 
-void initializeEventTracingForTools() {
-    if (FLAGS_trace.isEmpty()) {
-        return;
+void initializeEventTracingForTools(const char* traceFlag) {
+    if (!traceFlag) {
+        if (FLAGS_trace.isEmpty()) {
+            return;
+        }
+        traceFlag = FLAGS_trace[0];
     }
 
-    const char* traceFlag = FLAGS_trace[0];
     SkEventTracer* eventTracer = nullptr;
     if (0 == strcmp(traceFlag, "atrace")) {
         eventTracer = new SkATrace();
diff --git a/tools/trace/SkEventTracingPriv.h b/tools/trace/SkEventTracingPriv.h
index aa3ee6d4d9..fb7b2f3fa5 100644
--- a/tools/trace/SkEventTracingPriv.h
+++ b/tools/trace/SkEventTracingPriv.h
@@ -11,9 +11,10 @@
 #include "SkMutex.h"
 
 /**
- * Construct and install an SkEventTracer, based on the 'trace' command line argument.
+ * Construct and install an SkEventTracer, based on the mode,
+ * defaulting to the --trace command line argument.
  */
-void initializeEventTracingForTools();
+void initializeEventTracingForTools(const char* mode = nullptr);
 
 /**
  * Helper class used by internal implementations of SkEventTracer to manage categories.