Start calling v8 API SetDetachedWindowReason

This enables v8-side tracking of JS function calls made within a context
of a detached window.

Such calls should be rare, but if our predictions are incorrect, the
tracking code may impact performance of function calls. Therefore,
this is implemented behind finch experiments SetDetachedWindowReasonBy*
(enabled by default, but it'll give as an opportunity to disable
tracking or limit % of participating users, if needed).

Bug: 1018156
Change-Id: I878e6f1fabdeb229531af688fea0a5bc7412a145
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1895017
Commit-Queue: Bartek Nowierski <bartekn@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Keishi Hattori <keishi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712517}

third_party/blink/common/features.cc

@@ -410,5 +410,15 @@ const base::Feature kCompositeCrossOriginIframes{
 const base::Feature kSetLowPriorityForBeacon{"SetLowPriorityForBeacon",
                                              base::FEATURE_DISABLED_BY_DEFAULT};
 
+// When enabled, JS function calls in a detached window will be reported.
+// Reporting has a non-zero probability of a performance impact, hence an easy
+// way to disable it may come in handy.
+const base::Feature kSetDetachedWindowReasonByNavigation{
+    "SetDetachedWindowReasonByNavigation", base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kSetDetachedWindowReasonByClosing{
+    "SetDetachedWindowReasonByClosing", base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kSetDetachedWindowReasonByOtherReason{
+    "SetDetachedWindowReasonByOtherReason", base::FEATURE_ENABLED_BY_DEFAULT};
+
 }  // namespace features
 }  // namespace blink

third_party/blink/public/common/features.h

@@ -134,6 +134,13 @@ BLINK_COMMON_EXPORT extern const base::Feature kSubresourceRedirect;
 
 BLINK_COMMON_EXPORT extern const base::Feature kSetLowPriorityForBeacon;
 
+BLINK_COMMON_EXPORT extern const base::Feature
+    kSetDetachedWindowReasonByNavigation;
+BLINK_COMMON_EXPORT extern const base::Feature
+    kSetDetachedWindowReasonByClosing;
+BLINK_COMMON_EXPORT extern const base::Feature
+    kSetDetachedWindowReasonByOtherReason;
+
 }  // namespace features
 }  // namespace blink
 

third_party/blink/renderer/bindings/core/v8/local_window_proxy.cc

@@ -30,6 +30,7 @@
 
 #include "third_party/blink/renderer/bindings/core/v8/local_window_proxy.h"
 
+#include "third_party/blink/public/common/features.h"
 #include "third_party/blink/renderer/bindings/core/v8/isolated_world_csp.h"
 #include "third_party/blink/renderer/bindings/core/v8/script_controller.h"
 #include "third_party/blink/renderer/bindings/core/v8/to_v8_for_core.h"
@@ -78,8 +79,29 @@ void LocalWindowProxy::Trace(blink::Visitor* visitor) {
   WindowProxy::Trace(visitor);
 }
 
-void LocalWindowProxy::DisposeContext(Lifecycle next_status,
-                                      FrameReuseStatus frame_reuse_status) {
+bool LocalWindowProxy::IsSetDetachedWindowReasonEnabled(
+    v8::Context::DetachedWindowReason reason) {
+  switch (reason) {
+    case v8::Context::DetachedWindowReason::kWindowNotDetached:
+      // This shouldn't happen, but if it does, it's always safe to clear the
+      // reason.
+      return true;
+    case v8::Context::DetachedWindowReason::kDetachedWindowByNavigation:
+      return base::FeatureList::IsEnabled(
+          features::kSetDetachedWindowReasonByNavigation);
+    case v8::Context::DetachedWindowReason::kDetachedWindowByClosing:
+      return base::FeatureList::IsEnabled(
+          features::kSetDetachedWindowReasonByClosing);
+    case v8::Context::DetachedWindowReason::kDetachedWindowByOtherReason:
+      return base::FeatureList::IsEnabled(
+          features::kSetDetachedWindowReasonByOtherReason);
+  }
+}
+
+void LocalWindowProxy::DisposeContext(
+    Lifecycle next_status,
+    FrameReuseStatus frame_reuse_status,
+    v8::Context::DetachedWindowReason reason) {
   DCHECK(next_status == Lifecycle::kV8MemoryIsForciblyPurged ||
          next_status == Lifecycle::kGlobalObjectIsDetached ||
          next_status == Lifecycle::kFrameIsDetached ||
@@ -126,6 +148,10 @@ void LocalWindowProxy::DisposeContext(Lifecycle next_status,
 #endif
   }
 
+  if (IsSetDetachedWindowReasonEnabled(reason)) {
+    context->SetDetachedWindowReason(reason);
+  }
+
   script_state_->DisposePerContextData();
   // It's likely that disposing the context has created a lot of
   // garbage. Notify V8 about this so it'll have a chance of cleaning

third_party/blink/renderer/bindings/core/v8/local_window_proxy.h

@@ -69,7 +69,11 @@ class LocalWindowProxy final : public WindowProxy {
  private:
   bool IsLocal() const override { return true; }
   void Initialize() override;
-  void DisposeContext(Lifecycle next_status, FrameReuseStatus) override;
+  void DisposeContext(Lifecycle next_status,
+                      FrameReuseStatus,
+                      v8::Context::DetachedWindowReason) override;
+  static bool IsSetDetachedWindowReasonEnabled(
+      v8::Context::DetachedWindowReason reason);
 
   // Creates a new v8::Context with the window wrapper object as the global
   // object (aka the inner global).  Note that the window wrapper and its

third_party/blink/renderer/bindings/core/v8/remote_window_proxy.cc

@@ -49,7 +49,8 @@ RemoteWindowProxy::RemoteWindowProxy(v8::Isolate* isolate,
     : WindowProxy(isolate, frame, std::move(world)) {}
 
 void RemoteWindowProxy::DisposeContext(Lifecycle next_status,
-                                       FrameReuseStatus) {
+                                       FrameReuseStatus,
+                                       v8::Context::DetachedWindowReason) {
   DCHECK(next_status == Lifecycle::kV8MemoryIsForciblyPurged ||
          next_status == Lifecycle::kGlobalObjectIsDetached ||
          next_status == Lifecycle::kFrameIsDetached ||

third_party/blink/renderer/bindings/core/v8/remote_window_proxy.h

@@ -49,7 +49,9 @@ class RemoteWindowProxy final : public WindowProxy {
 
  private:
   void Initialize() override;
-  void DisposeContext(Lifecycle next_status, FrameReuseStatus) override;
+  void DisposeContext(Lifecycle next_status,
+                      FrameReuseStatus,
+                      v8::Context::DetachedWindowReason) override;
 
   // Creates a new v8::Context with the window wrapper object as the global
   // object (aka the inner global).  Note that the window wrapper and its

third_party/blink/renderer/bindings/core/v8/window_proxy.cc

@@ -65,19 +65,24 @@ void WindowProxy::ClearForClose() {
   DisposeContext(lifecycle_ == Lifecycle::kV8MemoryIsForciblyPurged
                      ? Lifecycle::kFrameIsDetachedAndV8MemoryIsPurged
                      : Lifecycle::kFrameIsDetached,
-                 kFrameWillNotBeReused);
+                 kFrameWillNotBeReused,
+                 v8::Context::DetachedWindowReason::kDetachedWindowByClosing);
 }
 
 void WindowProxy::ClearForNavigation() {
-  DisposeContext(Lifecycle::kGlobalObjectIsDetached, kFrameWillBeReused);
+  DisposeContext(Lifecycle::kGlobalObjectIsDetached, kFrameWillBeReused,
+                 v8::Context::kDetachedWindowByNavigation);
 }
 
 void WindowProxy::ClearForSwap() {
-  DisposeContext(Lifecycle::kGlobalObjectIsDetached, kFrameWillNotBeReused);
+  // This happens on a navigation between local/remote source.
+  DisposeContext(Lifecycle::kGlobalObjectIsDetached, kFrameWillNotBeReused,
+                 v8::Context::kDetachedWindowByNavigation);
 }
 
 void WindowProxy::ClearForV8MemoryPurge() {
-  DisposeContext(Lifecycle::kV8MemoryIsForciblyPurged, kFrameWillNotBeReused);
+  DisposeContext(Lifecycle::kV8MemoryIsForciblyPurged, kFrameWillNotBeReused,
+                 v8::Context::kDetachedWindowByOtherReason);
 }
 
 v8::Local<v8::Object> WindowProxy::GlobalProxyIfNotDetached() {

third_party/blink/renderer/bindings/core/v8/window_proxy.h

@@ -256,7 +256,9 @@ class WindowProxy : public GarbageCollected<WindowProxy> {
 
   virtual void Initialize() = 0;
 
-  virtual void DisposeContext(Lifecycle next_status, FrameReuseStatus) = 0;
+  virtual void DisposeContext(Lifecycle next_status,
+                              FrameReuseStatus,
+                              v8::Context::DetachedWindowReason) = 0;
 
   WARN_UNUSED_RESULT v8::Local<v8::Object> AssociateWithWrapper(
       DOMWindow*,