Revert "Start calling v8 API SetDetachedWindowReason"

This reverts commit a4168673.

Reason for revert: Instrumentation no longer needed. It was meant only for 1 milestone.

Original change's description:
> 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}

TBR=yukishiino@chromium.org,rkaplow@chromium.org,tasak@google.com,haraken@chromium.org,keishi@chromium.org,bartekn@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1018156
Change-Id: I35c58011a6ff0984c339393b083a48d13b6b3f12
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000404Reviewed-by: Keishi Hattori <keishi@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Keishi Hattori <keishi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731873}

third_party/blink/common/features.cc

@@ -411,16 +411,6 @@ const base::Feature kVizHitTestOcclusionCheck{
 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};
-
 // When enabled allows the header name used in the blink
 // CacheStorageCodeCacheHint runtime feature to be modified.  This runtime
 // feature disables generating full code cache for responses stored in

third_party/blink/public/common/features.h

@@ -133,13 +133,6 @@ 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;
-
 BLINK_COMMON_EXPORT extern const base::Feature kCacheStorageCodeCacheHintHeader;
 BLINK_COMMON_EXPORT extern const base::FeatureParam<std::string>
     kCacheStorageCodeCacheHintHeaderName;

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

@@ -31,7 +31,6 @@
 #include "third_party/blink/renderer/bindings/core/v8/local_window_proxy.h"
 
 #include "base/debug/dump_without_crashing.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"
@@ -80,29 +79,8 @@ void LocalWindowProxy::Trace(blink::Visitor* visitor) {
   WindowProxy::Trace(visitor);
 }
 
-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) {
+void LocalWindowProxy::DisposeContext(Lifecycle next_status,
+                                      FrameReuseStatus frame_reuse_status) {
   DCHECK(next_status == Lifecycle::kV8MemoryIsForciblyPurged ||
          next_status == Lifecycle::kGlobalObjectIsDetached ||
          next_status == Lifecycle::kFrameIsDetached ||
@@ -149,10 +127,6 @@ void LocalWindowProxy::DisposeContext(
 #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

@@ -70,11 +70,7 @@ class LocalWindowProxy final : public WindowProxy {
  private:
   bool IsLocal() const override { return true; }
   void Initialize() override;
-  void DisposeContext(Lifecycle next_status,
-                      FrameReuseStatus,
-                      v8::Context::DetachedWindowReason) override;
-  static bool IsSetDetachedWindowReasonEnabled(
-      v8::Context::DetachedWindowReason reason);
+  void DisposeContext(Lifecycle next_status, FrameReuseStatus) 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/remote_window_proxy.cc

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

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

@@ -49,9 +49,7 @@ class RemoteWindowProxy final : public WindowProxy {
 
  private:
   void Initialize() override;
-  void DisposeContext(Lifecycle next_status,
-                      FrameReuseStatus,
-                      v8::Context::DetachedWindowReason) override;
+  void DisposeContext(Lifecycle next_status, FrameReuseStatus) 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

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

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

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