Add experimental code behind a flag for Content Size Policy

content/browser/loader/content_size_resource_handler_manager.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/loader/content_size_resource_handler_manager.h"
+
+#include "base/bind.h"
+#include "base/stl_util.h"
+#include "content/browser/loader/content_size_frame_counter.h"
+#include "content/browser/loader/content_size_resource_handler.h"
+#include "content/browser/loader/resource_request_info_impl.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/url_request/url_request.h"
+
+namespace content {
+
+ContentSizeResourceHandlerManager::ContentSizeResourceHandlerManager()
+    : pending_updates_(new std::map<GlobalFrameRoutingId, uint64_t>) {}
+ContentSizeResourceHandlerManager::~ContentSizeResourceHandlerManager() {}
+
+std::unique_ptr<ResourceHandler>
+ContentSizeResourceHandlerManager::MaybeAddHandler(
+    std::unique_ptr<ResourceHandler> next_handler,
+    net::URLRequest* request) {
+  ResourceRequestInfoImpl* info = ResourceRequestInfoImpl::ForRequest(request);
+  DCHECK(info);
+  if (info->IsMainFrame())
+    return next_handler;
+
+  if (ContainsKey(frame_limits_, info->GetGlobalFrameRoutingId())) {
+    next_handler.reset(
+        new ContentSizeResourceHandler(std::move(next_handler), request, this));
+  }
+  return next_handler;
+}
+
+bool ContentSizeResourceHandlerManager::ShouldCancelRequest(
+    ResourceRequestInfoImpl* request_info,
+    uint64_t bytes_read) {
+  const GlobalFrameRoutingId& id = request_info->GetGlobalFrameRoutingId();
+  (*pending_updates_)[id] += bytes_read;
+
+  auto it = frame_limits_.find(id);
+  if (it == frame_limits_.end()) {
+    return false;
+  } else if (it->second > bytes_read) {
+    it->second -= bytes_read;
+    return false;
+  } else {
+    it->second = 0;
+    return true;
+  }
+}
+
+void ContentSizeResourceHandlerManager::NotifyUIThreadReadUpdates() {
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&ContentSizeFrameCounter::UpdateGlobalDataAccounting,
+                 base::Passed(std::move(pending_updates_))));
+  pending_updates_.reset(new std::map<GlobalFrameRoutingId, uint64_t>);
+}
+
+void ContentSizeResourceHandlerManager::FrameHasSizeLimit(
+    const GlobalFrameRoutingId& id,
+    uint64_t limit) {
+  frame_limits_[id] = limit;
+}
+
+void ContentSizeResourceHandlerManager::FramesWentOverSizeLimits(
+    std::unique_ptr<std::set<GlobalFrameRoutingId>> ids) {
+  for (const auto& it : *ids) {
+    FrameHasSizeLimit(it, 0);
+  }
+}
+
+void ContentSizeResourceHandlerManager::FrameDeleted(
+    const GlobalFrameRoutingId& id) {
+  frame_limits_.erase(id);
+}
+
+}  // namespace content