Further instrumentations to locate the jank source

content/browser/gpu/shader_disk_cache.cc

Index: content/browser/gpu/shader_disk_cache.cc
diff --git a/content/browser/gpu/shader_disk_cache.cc b/content/browser/gpu/shader_disk_cache.cc
index a50e3c38b982d050459641bded941488a830ed78..24f07035bfe846f209a33766c9da81283f5362ad 100644
--- a/content/browser/gpu/shader_disk_cache.cc
+++ b/content/browser/gpu/shader_disk_cache.cc
@@ -296,6 +296,11 @@ void ShaderDiskReadHelper::OnOpComplete(int rv) {
 }
 
 int ShaderDiskReadHelper::OpenNextEntry() {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422516 ShaderDiskReadHelper::OpenNextEntry"));
+
   DCHECK(CalledOnValidThread());
   // Called through OnOpComplete, so we know |cache_| is valid.
   op_type_ = OPEN_NEXT_COMPLETE;
@@ -306,6 +311,11 @@ int ShaderDiskReadHelper::OpenNextEntry() {
 }
 
 int ShaderDiskReadHelper::OpenNextEntryComplete(int rv) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422516 ShaderDiskReadHelper::OpenNextEntryComplete"));
+
   DCHECK(CalledOnValidThread());
   // Called through OnOpComplete, so we know |cache_| is valid.
   if (rv == net::ERR_FAILED) {
@@ -328,6 +338,11 @@ int ShaderDiskReadHelper::OpenNextEntryComplete(int rv) {
 }
 
 int ShaderDiskReadHelper::ReadComplete(int rv) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422516 ShaderDiskReadHelper::ReadComplete"));
+
   DCHECK(CalledOnValidThread());
   // Called through OnOpComplete, so we know |cache_| is valid.
   if (rv && rv == buf_->size()) {
@@ -346,6 +361,11 @@ int ShaderDiskReadHelper::ReadComplete(int rv) {
 }
 
 int ShaderDiskReadHelper::IterationComplete(int rv) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422516 ShaderDiskReadHelper::IterationComplete"));
+
   DCHECK(CalledOnValidThread());
   // Called through OnOpComplete, so we know |cache_| is valid.
   iter_.reset();