[Storage] Added tracing for blob creation

content/child/webblobregistry_impl.cc

Index: content/child/webblobregistry_impl.cc
diff --git a/content/child/webblobregistry_impl.cc b/content/child/webblobregistry_impl.cc
index 3bece44e01aa03acc0194b38793e89c0301c8590..828d18d489b55f41fc66014b71b101685c1a005c 100644
--- a/content/child/webblobregistry_impl.cc
+++ b/content/child/webblobregistry_impl.cc
@@ -9,10 +9,10 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
+#include "base/trace_event/trace_event.h"
 #include "content/child/child_thread_impl.h"
 #include "content/child/thread_safe_sender.h"
 #include "content/common/fileapi/webblob_messages.h"
-#include "storage/common/data_element.h"
 #include "third_party/WebKit/public/platform/WebBlobData.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebThreadSafeData.h"
@@ -34,6 +34,7 @@ const size_t kMaxSharedMemoryBytes = 10 * 1024 * 1024;
 
 WebBlobRegistryImpl::WebBlobRegistryImpl(ThreadSafeSender* sender)
     : sender_(sender) {
+  TRACE_EVENT0("Storage.Blob", "Init");

[michaeln, 2015/03/09 21:22:02]

this one is probably not so interesting, it happens once at the beginning of the
process

[dmurph, 2015/03/10 00:39:09]

This is to get the category to show up in the tracing viewer.  We do the same
thing in indexeddb, it's just to register the category.

 }
 
 WebBlobRegistryImpl::~WebBlobRegistryImpl() {
@@ -41,6 +42,7 @@ WebBlobRegistryImpl::~WebBlobRegistryImpl() {
 
 void WebBlobRegistryImpl::registerBlobData(
     const blink::WebString& uuid, const blink::WebBlobData& data) {
+  TRACE_EVENT0("Storage.Blob", "RegisterBlobData");
   const std::string uuid_str(uuid.utf8());
 
   storage::DataElement data_buffer;