[PM] Add node descriptions to graph dump protocol.

Bug: 1068233
Change-Id: Ie7b4dd8e6743dd963b8d94056bf71366c8633265
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2139438
Commit-Queue: Sigurður Ásgeirsson <siggi@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Joe Mason <joenotcharles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758809}

chrome/browser/ui/webui/discards/discards.mojom

@@ -104,7 +104,12 @@ struct PageInfo {
 
   url.mojom.Url main_frame_url;
 
-  // TODO(siggi): Estimate data.
+  // This field is a dictionary of values, where each value is generated by
+  // a performance_manager::NodeDataDescriber implementation and keyed by the
+  // name it registered with. The intent is for each describer to describe
+  // private node-related or node-attached data in some way, to allow presenting
+  // otherwise hidden state in the chrome://discards/graph view.
+  string description_json;
 };
 
 // Represents the momentary state of a Frame node.
@@ -115,6 +120,9 @@ struct FrameInfo {
   int64 page_id;
   int64 parent_frame_id;
   int64 process_id;
+
+  // See PageInfo::description_json.
+  string description_json;
 };
 
 // Represents the momentary state of a Process node.
@@ -123,6 +131,9 @@ struct ProcessInfo {
 
   mojo_base.mojom.ProcessId pid;
   uint64 private_footprint_kb;
+
+  // See PageInfo::description_json.
+  string description_json;
 };
 
 // Represents the momentary state of a Worker node.
@@ -135,6 +146,9 @@ struct WorkerInfo {
   array<int64> client_frame_ids;
   array<int64> client_worker_ids;
   array<int64> child_worker_ids;
+
+  // See PageInfo::description_json.
+  string description_json;
 };
 
 // Used to transport favicon data.

chrome/browser/ui/webui/discards/graph_dump_impl.cc

@@ -9,6 +9,7 @@
 
 #include "base/base64.h"
 #include "base/bind.h"
+#include "base/json/json_string_value_serializer.h"
 #include "base/macros.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "base/task/post_task.h"
@@ -19,6 +20,8 @@
 #include "components/favicon/core/favicon_service.h"
 #include "components/favicon_base/favicon_callback.h"
 #include "components/performance_manager/public/graph/graph.h"
+#include "components/performance_manager/public/graph/node_data_describer.h"
+#include "components/performance_manager/public/graph/node_data_describer_registry.h"
 #include "components/performance_manager/public/performance_manager.h"
 #include "components/performance_manager/public/web_contents_proxy.h"
 #include "content/public/browser/browser_task_traits.h"
@@ -35,6 +38,16 @@ int64_t GetSerializationId(const performance_manager::Node* node) {
   return performance_manager::Node::GetSerializationId(node);
 }
 
+// Best effort convert |value| to a string.
+std::string ToJSON(const base::Value& value) {
+  std::string result;
+  JSONStringValueSerializer serializer(&result);
+  if (serializer.Serialize(value))
+    return result;
+
+  return std::string();
+}
+
 }  // namespace
 
 class DiscardsGraphDumpImpl::FaviconRequestHelper {
@@ -372,6 +385,8 @@ void DiscardsGraphDumpImpl::SendFrameNotification(
   frame_info->page_id = GetSerializationId(page);
 
   frame_info->url = frame->GetURL();
+  frame_info->description_json = ToJSON(
+      graph_->GetNodeDataDescriberRegistry()->DescribeFrameNodeData(frame));
 
   if (created)
     change_subscriber_->FrameCreated(std::move(frame_info));
@@ -388,6 +403,9 @@ void DiscardsGraphDumpImpl::SendPageNotification(
 
   page_info->id = GetSerializationId(page_node);
   page_info->main_frame_url = page_node->GetMainFrameUrl();
+  page_info->description_json = ToJSON(
+      graph_->GetNodeDataDescriberRegistry()->DescribePageNodeData(page_node));
+
   if (created)
     change_subscriber_->PageCreated(std::move(page_info));
   else
@@ -405,6 +423,9 @@ void DiscardsGraphDumpImpl::SendProcessNotification(
   process_info->pid = process->GetProcessId();
   process_info->private_footprint_kb = process->GetPrivateFootprintKb();
 
+  process_info->description_json = ToJSON(
+      graph_->GetNodeDataDescriberRegistry()->DescribeProcessNodeData(process));
+
   if (created)
     change_subscriber_->ProcessCreated(std::move(process_info));
   else
@@ -435,6 +456,9 @@ void DiscardsGraphDumpImpl::SendWorkerNotification(
     worker_info->child_worker_ids.push_back(GetSerializationId(child_worker));
   }
 
+  worker_info->description_json = ToJSON(
+      graph_->GetNodeDataDescriberRegistry()->DescribeWorkerNodeData(worker));
+
   if (created)
     change_subscriber_->WorkerCreated(std::move(worker_info));
   else

chrome/browser/ui/webui/discards/graph_dump_impl_unittest.cc

@@ -8,11 +8,14 @@
 #include <set>
 #include <utility>
 
+#include "base/json/json_reader.h"
 #include "base/run_loop.h"
 #include "base/stl_util.h"
 #include "base/test/bind_test_util.h"
 #include "base/time/time.h"
 #include "chrome/browser/ui/webui/discards/discards.mojom.h"
+#include "components/performance_manager/public/graph/node_data_describer.h"
+#include "components/performance_manager/public/graph/node_data_describer_registry.h"
 #include "components/performance_manager/test_support/graph_impl.h"
 #include "components/performance_manager/test_support/mock_graphs.h"
 #include "content/public/test/browser_task_environment.h"
@@ -26,7 +29,7 @@ namespace {
 
 using performance_manager::NodeBase;
 
-const std::string kHtmlMimeType = "text/html";
+const char kHtmlMimeType[] = "text/html";
 
 class TestChangeStream : public discards::mojom::GraphChangeStream {
  public:
@@ -139,6 +142,31 @@ class DiscardsGraphDumpImplTest : public testing::Test {
   performance_manager::TestGraphImpl graph_;
 };
 
+class TestNodeDataDescriber : public performance_manager::NodeDataDescriber {
+ public:
+  // NodeDataDescriber implementations:
+  base::Value DescribeFrameNodeData(
+      const performance_manager::FrameNode* node) const override {
+    return base::Value("frame");
+  }
+  base::Value DescribePageNodeData(
+      const performance_manager::PageNode* node) const override {
+    return base::Value("page");
+  }
+  base::Value DescribeProcessNodeData(
+      const performance_manager::ProcessNode* node) const override {
+    return base::Value("process");
+  }
+  base::Value DescribeSystemNodeData(
+      const performance_manager::SystemNode* node) const override {
+    return base::Value("system");
+  }
+  base::Value DescribeWorkerNodeData(
+      const performance_manager::WorkerNode* node) const override {
+    return base::Value("worker");
+  }
+};
+
 }  // namespace
 
 TEST_F(DiscardsGraphDumpImplTest, ChangeStream) {
@@ -175,6 +203,9 @@ TEST_F(DiscardsGraphDumpImplTest, ChangeStream) {
   impl->BindWithGraph(&graph_, graph_dump_remote.BindNewPipeAndPassReceiver());
   graph_.PassToGraph(std::move(impl));
 
+  TestNodeDataDescriber describer;
+  graph_.GetNodeDataDescriberRegistry()->RegisterDescriber(&describer, "test");
+
   TestChangeStream change_stream;
   graph_dump_remote->SubscribeToChanges(change_stream.GetRemote());
 
@@ -186,11 +217,22 @@ TEST_F(DiscardsGraphDumpImplTest, ChangeStream) {
 
   EXPECT_EQ(2u, change_stream.process_map().size());
   for (const auto& kv : change_stream.process_map()) {
-    EXPECT_NE(0u, kv.second->id);
+    const auto* process_info = kv.second.get();
+    EXPECT_NE(0u, process_info->id);
+    EXPECT_EQ(base::JSONReader::Read("{\"test\":\"process\"}"),
+              base::JSONReader::Read(process_info->description_json));
   }
 
   EXPECT_EQ(3u, change_stream.frame_map().size());
+  for (const auto& kv : change_stream.frame_map()) {
+    EXPECT_EQ(base::JSONReader::Read("{\"test\":\"frame\"}"),
+              base::JSONReader::Read(kv.second->description_json));
+  }
   EXPECT_EQ(1u, change_stream.worker_map().size());
+  for (const auto& kv : change_stream.worker_map()) {
+    EXPECT_EQ(base::JSONReader::Read("{\"test\":\"worker\"}"),
+              base::JSONReader::Read(kv.second->description_json));
+  }
 
   // Count the top-level frames as we go.
   size_t top_level_frames = 0;
@@ -218,6 +260,8 @@ TEST_F(DiscardsGraphDumpImplTest, ChangeStream) {
     const auto& page = kv.second;
     EXPECT_NE(0u, page->id);
     EXPECT_EQ(kExampleUrl, page->main_frame_url);
+    EXPECT_EQ(base::JSONReader::Read("{\"test\":\"page\"}"),
+              base::JSONReader::Read(kv.second->description_json));
   }
 
   // Test change notifications.
@@ -249,4 +293,6 @@ TEST_F(DiscardsGraphDumpImplTest, ChangeStream) {
   EXPECT_EQ(nullptr, graph_.TakeFromGraph(impl_raw));
 
   worker->RemoveClientFrame(mock_graph.frame.get());
+
+  graph_.GetNodeDataDescriberRegistry()->UnregisterDescriber(&describer);
 }