Remove obsolete NetworkContext::DiskCheck code.

Bug: 711579
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: If272f72850da85b7959df00de5c1b5f97600f520
Reviewed-on: https://chromium-review.googlesource.com/830653Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524734}

content/network/network_context.cc

@@ -7,12 +7,9 @@
 #include <memory>
 
 #include "base/command_line.h"
-#include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram_macros.h"
 #include "base/optional.h"
-#include "base/rand_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/task_scheduler/task_traits.h"
@@ -82,11 +79,6 @@ NetworkContext::NetworkContext(
     : network_service_(network_service),
       params_(std::move(params)),
       binding_(this, std::move(request)) {
-  if (params_ && params_->http_cache_path) {
-    // Only sample 0.1% of NetworkContexts that get created.
-    if (base::RandUint64() % 1000 == 0)
-      disk_checker_ = std::make_unique<DiskChecker>(*params_->http_cache_path);
-  }
   network_service_->RegisterNetworkContext(this);
   ApplyContextParamsToBuilder(builder.get(), params_.get());
   owned_url_request_context_ = builder->Build();
@@ -186,30 +178,6 @@ void NetworkContext::OnConnectionError() {
     delete this;
 }
 
-NetworkContext::DiskChecker::DiskChecker(const base::FilePath& cache_path)
-    : cache_path_(cache_path) {
-  timer_.Start(FROM_HERE, base::TimeDelta::FromHours(24),
-               base::Bind(&DiskChecker::CheckDiskSize, base::Unretained(this)));
-
-  // Check disk size at startup, hopefully before the HTTPCache has been cleared
-  // from the previous run.
-  CheckDiskSize();
-}
-
-void NetworkContext::DiskChecker::CheckDiskSize() {
-  base::PostTaskWithTraits(
-      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
-      base::Bind(&DiskChecker::CheckDiskSizeOnBackgroundThread, cache_path_));
-}
-
-void NetworkContext::DiskChecker::CheckDiskSizeOnBackgroundThread(
-    const base::FilePath& cache_path) {
-  int64_t size = base::ComputeDirectorySize(cache_path);
-  UMA_HISTOGRAM_MEMORY_LARGE_MB("Net.DiskCache.Size", size / 1024 / 1024);
-}
-
-NetworkContext::DiskChecker::~DiskChecker() = default;
-
 std::unique_ptr<net::URLRequestContext> NetworkContext::MakeURLRequestContext(
     mojom::NetworkContextParams* network_context_params) {
   URLRequestContextBuilderMojo builder;

content/network/network_context.h

@@ -13,7 +13,6 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/time/time.h"
-#include "base/timer/timer.h"
 #include "content/common/content_export.h"
 #include "content/network/cookie_manager.h"
 #include "content/public/common/network_service.mojom.h"
@@ -145,24 +144,6 @@ class CONTENT_EXPORT NetworkContext : public mojom::NetworkContext {
 
   std::unique_ptr<CookieManager> cookie_manager_;
 
-  // Temporary class to help diagnose the impact of https://crbug.com/711579.
-  // Every 24-hours, measures the size of the network cache and emits an UMA
-  // metric.
-  class DiskChecker {
-   public:
-    explicit DiskChecker(const base::FilePath& cache_path);
-    ~DiskChecker();
-
-   private:
-    void CheckDiskSize();
-    static void CheckDiskSizeOnBackgroundThread(
-        const base::FilePath& cache_path);
-    base::RepeatingTimer timer_;
-    base::FilePath cache_path_;
-    DISALLOW_COPY_AND_ASSIGN(DiskChecker);
-  };
-  std::unique_ptr<DiskChecker> disk_checker_;
-
   DISALLOW_COPY_AND_ASSIGN(NetworkContext);
 };
 

tools/metrics/histograms/histograms.xml

@@ -42295,6 +42295,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Net.DiskCache.Size" units="MB">
+  <obsolete>
+    Removed in Chrome 65.
+  </obsolete>
   <owner>erikchen@chromium.org</owner>
   <summary>
     The sum of the size of all files in the HTTP cache directory.