Revert "Experiment: Add KeepAlive source histogram to crash keys."

This reverts commit 2629484.

Reason for revert: This shouldn't live past the branch, and we have the data we need.

Original change's description:
> Experiment: Add KeepAlive source histogram to crash keys.
>
> This re-lands the experiment first landed in
> https://chromium-review.googlesource.com/c/chromium/src/+/2705030 in
> an effort to discover the source of new no-BrowsingInstanceID
> failures.
>
> This CL will be reverted once the data has been logged.
>
> Bug: 1148542
> Change-Id: Ie387c8678fea9d13326bcc7360b9b8898523fda4
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2799974
> Commit-Queue: James MacLean <wjmaclean@chromium.org>
> Reviewed-by: Charlie Reis <creis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#868659}

(cherry picked from commit eb882a2)

Bug: 1148542
Change-Id: Id5d9b3a3623373bcbaf8105e1b1b179df42234e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2815263
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: James MacLean <wjmaclean@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#870794}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2826395
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/branch-heads/4472@{#66}
Cr-Branched-From: 3d60439-refs/heads/master@{#870763}

content/browser/child_process_security_policy_impl.cc

@@ -150,7 +150,7 @@ base::debug::CrashKeyString* GetKilledProcessOriginLockKey() {
 
 base::debug::CrashKeyString* GetCanAccessDataFailureReasonKey() {
   static auto* crash_key = base::debug::AllocateCrashKeyString(
-      "can_access_data_failure_reason", base::debug::CrashKeySize::Size256);
+      "can_access_data_failure_reason", base::debug::CrashKeySize::Size64);
   return crash_key;
 }
 
@@ -1654,18 +1654,9 @@ bool ChildProcessSecurityPolicyImpl::CanAccessDataForOrigin(
       // do not agree, the check might be slightly weaker (as the least common
       // denominator), but the differences must never violate the ProcessLock.
       if (security_state->browsing_instance_ids().empty()) {
-        // TODO(wjmaclean): Remove the keepalive source tracking after
-        // diagnosing the cause of the remaining reports in
-        // https://crbug.com/1148542.
-        RenderProcessHostImpl* child_host = static_cast<RenderProcessHostImpl*>(
-            RenderProcessHost::FromID(child_id));
-        DCHECK(child_host);
-        failure_reason =
-            base::StringPrintf("No BIids, keep_alive_count = %zu, sources = %s",
-                               child_host->keep_alive_ref_count(),
-                               child_host->keep_alive_sources().c_str());
+        failure_reason = "No BrowsingInstanceIDs.";
         // This will fall through to the call to
-        // LogCanAccessDataForOriginCrashKeys and then return false.
+        // LogCanAccessDataForOriginCrashKeys below, then return false.
       }
       for (auto browsing_instance_id :
            security_state->browsing_instance_ids()) {

content/browser/renderer_host/keep_alive_handle_factory.cc

@@ -31,17 +31,15 @@ class KeepAliveHandleImpl final : public blink::mojom::KeepAliveHandle {
     if (!process_host || process_host->IsKeepAliveRefCountDisabled()) {
       return;
     }
-    process_host->IncrementKeepAliveRefCount(
-        RenderProcessHost::KeepAliveSource::KEEP_ALIVE_HANDLE_FACTORY);
+    process_host->IncrementKeepAliveRefCount();
   }
   ~KeepAliveHandleImpl() override {
     GetContentClient()->browser()->OnKeepaliveRequestFinished();
     RenderProcessHost* process_host = RenderProcessHost::FromID(process_id_);
     if (!process_host || process_host->IsKeepAliveRefCountDisabled()) {
       return;
     }
-    process_host->DecrementKeepAliveRefCount(
-        RenderProcessHost::KeepAliveSource::KEEP_ALIVE_HANDLE_FACTORY);
+    process_host->DecrementKeepAliveRefCount();
   }
 
   KeepAliveHandleImpl(const KeepAliveHandleImpl&) = delete;

content/browser/renderer_host/render_process_host_impl.cc

@@ -2149,7 +2149,7 @@ void RenderProcessHostImpl::CreateWebSocketConnector(
 void RenderProcessHostImpl::CancelProcessShutdownDelayForUnload() {
   if (IsKeepAliveRefCountDisabled())
     return;
-  DecrementKeepAliveRefCount(KeepAliveSource::KEEP_ALIVE_SUBFRAME_UNLOAD);
+  DecrementKeepAliveRefCount();
 }
 
 void RenderProcessHostImpl::DelayProcessShutdownForUnload(
@@ -2158,7 +2158,7 @@ void RenderProcessHostImpl::DelayProcessShutdownForUnload(
   if (IsKeepAliveRefCountDisabled() || deleting_soon_ || fast_shutdown_started_)
     return;
 
-  IncrementKeepAliveRefCount(KeepAliveSource::KEEP_ALIVE_SUBFRAME_UNLOAD);
+  IncrementKeepAliveRefCount();
   GetUIThreadTaskRunner({})->PostDelayedTask(
       FROM_HERE,
       base::BindOnce(
@@ -2665,21 +2665,19 @@ bool RenderProcessHostImpl::IsProcessBackgrounded() {
   return priority_.is_background();
 }
 
-void RenderProcessHostImpl::IncrementKeepAliveRefCount(KeepAliveSource source) {
+void RenderProcessHostImpl::IncrementKeepAliveRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!is_keep_alive_ref_count_disabled_);
   ++keep_alive_ref_count_;
-  keep_alive_sources_ += base::StringPrintf("%d+", static_cast<int>(source));
   if (keep_alive_ref_count_ == 1)
     GetRendererInterface()->SetSchedulerKeepActive(true);
 }
 
-void RenderProcessHostImpl::DecrementKeepAliveRefCount(KeepAliveSource source) {
+void RenderProcessHostImpl::DecrementKeepAliveRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!is_keep_alive_ref_count_disabled_);
   DCHECK_GT(keep_alive_ref_count_, 0U);
   --keep_alive_ref_count_;
-  keep_alive_sources_ += base::StringPrintf("%d-", static_cast<int>(source));
   if (keep_alive_ref_count_ == 0) {
     Cleanup();
     GetRendererInterface()->SetSchedulerKeepActive(false);

content/browser/renderer_host/render_process_host_impl.h

@@ -241,8 +241,8 @@ class CONTENT_EXPORT RenderProcessHostImpl
       override;
   const base::TimeTicks& GetInitTimeForNavigationMetrics() override;
   bool IsProcessBackgrounded() override;
-  void IncrementKeepAliveRefCount(KeepAliveSource source) override;
-  void DecrementKeepAliveRefCount(KeepAliveSource source) override;
+  void IncrementKeepAliveRefCount() override;
+  void DecrementKeepAliveRefCount() override;
   void DisableKeepAliveRefCount() override;
   bool IsKeepAliveRefCountDisabled() override;
   mojom::Renderer* GetRendererInterface() override;
@@ -666,8 +666,6 @@ class CONTENT_EXPORT RenderProcessHostImpl
 #endif
 
   size_t keep_alive_ref_count() const { return keep_alive_ref_count_; }
-  // TODO(wjmaclean): remove this when the experiment is done.
-  std::string keep_alive_sources() const { return keep_alive_sources_; }
 
   // Allows overriding the URLLoaderFactory creation via CreateURLLoaderFactory.
   // Passing a null callback will restore the default behavior.
@@ -934,7 +932,6 @@ class CONTENT_EXPORT RenderProcessHostImpl
   mojo::OutgoingInvitation mojo_invitation_;
 
   size_t keep_alive_ref_count_;
-  std::string keep_alive_sources_;
 
   // Set in DisableKeepAliveRefCount(). When true, |keep_alive_ref_count_| must
   // no longer be modified.

content/browser/service_worker/service_worker_process_manager.cc

@@ -66,10 +66,8 @@ void ServiceWorkerProcessManager::Shutdown() {
     for (const auto& it : worker_process_map_) {
       if (it.second->HasProcess()) {
         RenderProcessHost* process = it.second->GetProcess();
-        if (!process->IsKeepAliveRefCountDisabled()) {
-          process->DecrementKeepAliveRefCount(
-              RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SERVICE_WORKER);
-        }
+        if (!process->IsKeepAliveRefCountDisabled())
+          process->DecrementKeepAliveRefCount();
       }
     }
   }
@@ -163,8 +161,7 @@ ServiceWorkerProcessManager::AllocateWorkerProcess(
 
   worker_process_map_.emplace(embedded_worker_id, std::move(site_instance));
   if (!rph->IsKeepAliveRefCountDisabled())
-    rph->IncrementKeepAliveRefCount(
-        RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SERVICE_WORKER);
+    rph->IncrementKeepAliveRefCount();
   out_info->process_id = rph->GetID();
   out_info->start_situation = start_situation;
   return blink::ServiceWorkerStatusCode::kOk;
@@ -193,10 +190,8 @@ void ServiceWorkerProcessManager::ReleaseWorkerProcess(int embedded_worker_id) {
 
   if (it->second->HasProcess()) {
     RenderProcessHost* process = it->second->GetProcess();
-    if (!process->IsKeepAliveRefCountDisabled()) {
-      process->DecrementKeepAliveRefCount(
-          RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SERVICE_WORKER);
-    }
+    if (!process->IsKeepAliveRefCountDisabled())
+      process->DecrementKeepAliveRefCount();
   }
   worker_process_map_.erase(it);
 }

content/browser/site_per_process_browsertest.cc

@@ -7676,8 +7676,7 @@ IN_PROC_BROWSER_TEST_P(SitePerProcessBrowserTest,
   // termination.
   RenderProcessHost* subframe_process =
       root->child_at(0)->current_frame_host()->GetProcess();
-  subframe_process->IncrementKeepAliveRefCount(
-      RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SUBFRAME_UNLOAD);
+  subframe_process->IncrementKeepAliveRefCount();
 
   // Navigate the subframe away from b.com.  Since this is the last active
   // frame in the b.com process, this causes the RenderWidget and RenderView to
@@ -7689,8 +7688,7 @@ IN_PROC_BROWSER_TEST_P(SitePerProcessBrowserTest,
   // Release the process.
   RenderProcessHostWatcher process_shutdown_observer(
       subframe_process, RenderProcessHostWatcher::WATCH_FOR_PROCESS_EXIT);
-  subframe_process->DecrementKeepAliveRefCount(
-      RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SUBFRAME_UNLOAD);
+  subframe_process->DecrementKeepAliveRefCount();
   process_shutdown_observer.Wait();
 }
 

content/browser/worker_host/shared_worker_host.cc

@@ -90,15 +90,12 @@ class SharedWorkerHost::ScopedProcessHostRef {
  public:
   explicit ScopedProcessHostRef(RenderProcessHost* render_process_host)
       : render_process_host_(render_process_host) {
-    render_process_host_->IncrementKeepAliveRefCount(
-        RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SHARED_WORKER);
+    render_process_host_->IncrementKeepAliveRefCount();
   }
 
   ~ScopedProcessHostRef() {
-    if (!render_process_host_->IsKeepAliveRefCountDisabled()) {
-      render_process_host_->DecrementKeepAliveRefCount(
-          RenderProcessHost::KeepAliveSource::KEEP_ALIVE_SHARED_WORKER);
-    }
+    if (!render_process_host_->IsKeepAliveRefCountDisabled())
+      render_process_host_->DecrementKeepAliveRefCount();
   }
 
   ScopedProcessHostRef(const ScopedProcessHostRef& other) = delete;

content/public/browser/render_process_host.h

@@ -122,15 +122,6 @@ class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
     GENERATE_CRASH_DUMP,
   };
 
-  // Temporary enum to track source of KeepAlive increments.
-  enum class KeepAliveSource {
-    KEEP_ALIVE_NONE,
-    KEEP_ALIVE_HANDLE_FACTORY,
-    KEEP_ALIVE_SUBFRAME_UNLOAD,
-    KEEP_ALIVE_SERVICE_WORKER,
-    KEEP_ALIVE_SHARED_WORKER
-  };
-
   // General functions ---------------------------------------------------------
 
   ~RenderProcessHost() override {}
@@ -404,8 +395,8 @@ class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
   //    Keeps the process alive briefly to give subframe unload handlers a
   //    chance to execute after their parent frame navigates or is detached.
   //    See https://crbug.com/852204.
-  virtual void IncrementKeepAliveRefCount(KeepAliveSource source) = 0;
-  virtual void DecrementKeepAliveRefCount(KeepAliveSource source) = 0;
+  virtual void IncrementKeepAliveRefCount() = 0;
+  virtual void DecrementKeepAliveRefCount() = 0;
 
   // Sets keep alive ref counts to zero. Called when the browser context will be
   // destroyed so this RenderProcessHost can immediately die.

content/public/test/mock_render_process_host.cc

@@ -362,11 +362,11 @@ size_t MockRenderProcessHost::GetKeepAliveRefCount() const {
   return keep_alive_ref_count_;
 }
 
-void MockRenderProcessHost::IncrementKeepAliveRefCount(KeepAliveSource source) {
+void MockRenderProcessHost::IncrementKeepAliveRefCount() {
   ++keep_alive_ref_count_;
 }
 
-void MockRenderProcessHost::DecrementKeepAliveRefCount(KeepAliveSource source) {
+void MockRenderProcessHost::DecrementKeepAliveRefCount() {
   --keep_alive_ref_count_;
 }
 

content/public/test/mock_render_process_host.h

@@ -143,8 +143,8 @@ class MockRenderProcessHost : public RenderProcessHost {
   const base::TimeTicks& GetInitTimeForNavigationMetrics() override;
   bool IsProcessBackgrounded() override;
   size_t GetKeepAliveRefCount() const;
-  void IncrementKeepAliveRefCount(KeepAliveSource source) override;
-  void DecrementKeepAliveRefCount(KeepAliveSource source) override;
+  void IncrementKeepAliveRefCount() override;
+  void DecrementKeepAliveRefCount() override;
   void DisableKeepAliveRefCount() override;
   bool IsKeepAliveRefCountDisabled() override;
   mojom::Renderer* GetRendererInterface() override;