Add experimental code behind a flag for Content Size Policy

content/browser/loader/content_size_frame_counter.cc

Index: content/browser/loader/content_size_frame_counter.cc
diff --git a/content/browser/loader/content_size_frame_counter.cc b/content/browser/loader/content_size_frame_counter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6c5e0f9512502b5b36ef93a56773ef107f218353
--- /dev/null
+++ b/content/browser/loader/content_size_frame_counter.cc
@@ -0,0 +1,189 @@
+// 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_frame_counter.h"
+
+#include "content/browser/frame_host/frame_tree.h"
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/loader/content_size_resource_handler_manager.h"
+#include "content/browser/loader/resource_dispatcher_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/common/content_switches.h"
+#include "url/origin.h"
+
+namespace content {
+
+ContentSizeFrameCounter::ContentSizeFrameCounter(WebContents* web_contents)
+    : WebContentsObserver(web_contents) {}
+
+ContentSizeFrameCounter::~ContentSizeFrameCounter() {}
+
+// TODO(csharrison): This code really wants to be in
+// WebContentsObserver::ReadyToCommitNavigation, which is not available yet.
+// Note: this code is all experimental. In the final version, the render process
+// will notify this component that a given frame should have its data counted.
+// This will likely be in a mojo interface callback. For now, count all
+// cross-origin frames as having a data limit set by a command line flag.
+void ContentSizeFrameCounter::DidFinishNavigation(
+    NavigationHandle* navigation_handle) {
+  if (!navigation_handle->HasCommitted() || navigation_handle->IsErrorPage())
+    return;
+  const GURL& url = navigation_handle->GetURL();
+  // Only consider http/s or about:blank urls for blocking.
+  if (!url.SchemeIsHTTPOrHTTPS() &&
+      url.spec().compare(url::kAboutBlankURL) != 0) {
+    return;
+  }
+
+  if (web_contents()->GetLastCommittedURL().SchemeIs("chrome"))
+    return;
+
+  // TODO(csharrison): Navigations to about:blank are not counted as
+  // same-origin.
+  if (url::Origin(web_contents()->GetLastCommittedURL())
+          .IsSameOriginWith(url::Origin(url))) {
+    return;
+  }
+
+  std::string policy_string =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          switches::kContentSizePolicy);
+  uint64_t content_size = 0;
+  base::StringToUint64(policy_string, &content_size);
+
+  RenderFrameHostImpl* rfh = static_cast<RenderFrameHostImpl*>(
+      navigation_handle->GetRenderFrameHost());
+  FrameSize* frame_size = AddNewFrame(rfh->frame_tree_node(), content_size);
+  if (frame_size->content_left < INT_MAX) {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&ContentSizeFrameCounter::NotifyFrameHasLimit,
+                   rfh->GetGlobalFrameRoutingId(), frame_size->content_left));
+  }
+}
+
+// static
+// This method iterates through all ContentSizeFrameCounters, and calls
+// UpdateDataAccounting on them with updates from the IO thread.
+void ContentSizeFrameCounter::UpdateGlobalDataAccounting(
+    std::unique_ptr<std::map<GlobalFrameRoutingId, uint64_t>> updates) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(updates);
+  std::map<ContentSizeFrameCounter*, std::map<GlobalFrameRoutingId, uint64_t>>
+      per_notifier_map;
+  for (const auto& it : *updates) {
+    RenderFrameHostImpl* rfh = RenderFrameHostImpl::FromID(
+        it.first.child_id, it.first.frame_routing_id);
+    WebContents* contents = WebContents::FromRenderFrameHost(rfh);
+    if (!contents)
+      continue;
+    ContentSizeFrameCounter* notifier =
+        static_cast<WebContentsImpl*>(contents)->content_size_frame_counter();
+    per_notifier_map[notifier][it.first] += it.second;
+  }
+  for (const auto& it : per_notifier_map) {
+    it.first->UpdateDataAccounting(it.second);
+  }
+}
+
+ContentSizeFrameCounter::FrameSize* ContentSizeFrameCounter::AddNewFrame(
+    FrameTreeNode* node,
+    uint64_t limit) {
+  FrameSize* min_parent_frame_size = nullptr;
+  for (FrameTreeNode* current_node = node->parent(); current_node != nullptr;
+       current_node = current_node->parent()) {
+    std::map<int, FrameSize>::iterator size_it =
+        frame_tree_node_sizes_.find(current_node->frame_tree_node_id());
+    if (size_it != frame_tree_node_sizes_.end() &&
+        (!min_parent_frame_size ||
+         size_it->second.content_left < min_parent_frame_size->content_left)) {
+      min_parent_frame_size = &size_it->second;
+    }
+  }
+
+  // No need to add this to the map if a parent frame has a lower limit.
+  if (min_parent_frame_size && min_parent_frame_size->content_left <= limit)
+    return min_parent_frame_size;
+  FrameSize* size = &frame_tree_node_sizes_[node->frame_tree_node_id()];
+  size->content_left = limit;
+  return size;
+}
+
+void ContentSizeFrameCounter::ApplyUpdateToTree(
+    FrameTreeNode* node,
+    uint64_t bytes_downloaded,
+    std::set<GlobalFrameRoutingId>* routing_ids_to_block) {
+  FrameTreeNode* highest_node_to_block = nullptr;
+  for (FrameTreeNode* current_node = node; current_node != nullptr;
+       current_node = current_node->parent()) {
+    std::map<int, FrameSize>::iterator size_it =
+        frame_tree_node_sizes_.find(current_node->frame_tree_node_id());
+    if (size_it == frame_tree_node_sizes_.end())
+      continue;
+
+    if (size_it->second.content_left < bytes_downloaded) {
+      size_it->second.content_left = 0;
+      highest_node_to_block = node;
+    } else {
+      size_it->second.content_left -= bytes_downloaded;
+    }
+  }
+
+  // No frame went over the size limit.
+  if (!highest_node_to_block)
+    return;
+
+  // Collect all the routing ids to block in the subtree defined by
+  // |highest_node_to_block|.
+  for (FrameTreeNode* ftn : highest_node_to_block->frame_tree()->SubtreeNodes(
+           highest_node_to_block)) {
+    routing_ids_to_block->insert(
+        ftn->current_frame_host()->GetGlobalFrameRoutingId());
+  }
+}
+
+void ContentSizeFrameCounter::UpdateDataAccounting(
+    std::map<GlobalFrameRoutingId, uint64_t> updates) {
+  std::unique_ptr<std::set<GlobalFrameRoutingId>> frames_over_limit(
+      new std::set<GlobalFrameRoutingId>);
+  for (const auto& it : updates) {
+    RenderFrameHostImpl* rfh = static_cast<RenderFrameHostImpl*>(
+        RenderFrameHost::FromID(it.first.child_id, it.first.frame_routing_id));
+    if (!rfh)
+      continue;
+    ApplyUpdateToTree(rfh->frame_tree_node(), it.second,
+                      frames_over_limit.get());
+  }
+  if (!frames_over_limit->empty()) {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&ContentSizeFrameCounter::NotifyFramesWentOverSizeLimits,
+                   base::Passed(std::move(frames_over_limit))));
+  }
+}
+
+// static
+void ContentSizeFrameCounter::NotifyFramesWentOverSizeLimits(
+    std::unique_ptr<std::set<GlobalFrameRoutingId>> frames) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  ResourceDispatcherHostImpl* rdh = ResourceDispatcherHostImpl::Get();
+  if (rdh && rdh->content_size_manager()) {
+    rdh->content_size_manager()->FramesWentOverSizeLimits(std::move(frames));
+  }
+}
+
+// static
+void ContentSizeFrameCounter::NotifyFrameHasLimit(
+    const GlobalFrameRoutingId& frame,
+    uint64_t limit) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  ResourceDispatcherHostImpl* rdh = ResourceDispatcherHostImpl::Get();
+  if (rdh && rdh->content_size_manager()) {
+    rdh->content_size_manager()->FrameHasSizeLimit(frame, limit);
+  }
+}
+
+}  // namespace content