[PM] Add additional helpers to PerformanceManagerBrowserHarness.

This adds OnGraphCreated test seams to the browser harness, as well as
a utility function for running a lambda synchronously in the graph
(a common operation in tests).

Change-Id: I4c10dbba34bc8c1d81722ac3780491079a8cadf6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2493687Reviewed-by: Joe Mason <joenotcharles@chromium.org>
Commit-Queue: Chris Hamilton <chrisha@chromium.org>
Auto-Submit: Chris Hamilton <chrisha@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821281}

components/performance_manager/embedder/performance_manager_lifetime.h

@@ -26,6 +26,10 @@ class PerformanceManagerLifetime {
   PerformanceManagerLifetime(Decorators, GraphCreatedCallback);
   ~PerformanceManagerLifetime();
 
+  // Allows specifying an additional callback that will be invoked in tests.
+  static void SetAdditionalGraphCreatedCallbackForTesting(
+      GraphCreatedCallback graph_created_callback);
+
  private:
   std::unique_ptr<PerformanceManager> performance_manager_;
   std::unique_ptr<PerformanceManagerRegistry> performance_manager_registry_;

components/performance_manager/performance_manager_lifetime.cc

@@ -5,6 +5,7 @@
 #include "components/performance_manager/embedder/performance_manager_lifetime.h"
 
 #include "base/bind.h"
+#include "base/no_destructor.h"
 #include "base/notreached.h"
 #include "build/build_config.h"
 #include "components/performance_manager/decorators/frame_visibility_decorator.h"
@@ -27,6 +28,12 @@ namespace performance_manager {
 
 namespace {
 
+GraphCreatedCallback* GetAdditionalGraphCreatedCallback() {
+  static base::NoDestructor<GraphCreatedCallback>
+      additional_graph_created_callback;
+  return additional_graph_created_callback.get();
+}
+
 void DefaultGraphCreatedCallback(
     GraphCreatedCallback external_graph_created_callback,
     GraphImpl* graph) {
@@ -43,13 +50,19 @@ void DefaultGraphCreatedCallback(
 #if !defined(OS_ANDROID)
   graph->PassToGraph(std::make_unique<SiteDataRecorder>());
 #endif
+
+  // Run graph created callbacks.
   std::move(external_graph_created_callback).Run(graph);
+  if (*GetAdditionalGraphCreatedCallback())
+    std::move(*GetAdditionalGraphCreatedCallback()).Run(graph);
 }
 
 void NullGraphCreatedCallback(
     GraphCreatedCallback external_graph_created_callback,
     GraphImpl* graph) {
   std::move(external_graph_created_callback).Run(graph);
+  if (*GetAdditionalGraphCreatedCallback())
+    std::move(*GetAdditionalGraphCreatedCallback()).Run(graph);
 }
 
 base::OnceCallback<void(GraphImpl*)> AddDecorators(
@@ -84,6 +97,12 @@ PerformanceManagerLifetime::~PerformanceManagerLifetime() {
       std::move(performance_manager_));
 }
 
+// static
+void PerformanceManagerLifetime::SetAdditionalGraphCreatedCallbackForTesting(
+    GraphCreatedCallback graph_created_callback) {
+  *GetAdditionalGraphCreatedCallback() = std::move(graph_created_callback);
+}
+
 std::unique_ptr<PerformanceManager>
 CreatePerformanceManagerWithDefaultDecorators(
     GraphCreatedCallback graph_created_callback) {

components/performance_manager/test_support/performance_manager_browsertest_harness.cc

@@ -6,6 +6,7 @@
 
 #include "base/bind_helpers.h"
 #include "base/run_loop.h"
+#include "components/performance_manager/embedder/performance_manager_lifetime.h"
 #include "content/public/common/content_switches.h"
 #include "content/shell/browser/shell.h"
 #include "content/shell/browser/shell_content_browser_client.h"
@@ -20,6 +21,16 @@ namespace performance_manager {
 PerformanceManagerBrowserTestHarness::~PerformanceManagerBrowserTestHarness() =
     default;
 
+void PerformanceManagerBrowserTestHarness::SetUp() {
+  PerformanceManagerLifetime::SetAdditionalGraphCreatedCallbackForTesting(
+      base::BindLambdaForTesting(
+          [self = this](Graph* graph) { self->OnGraphCreated(graph); }));
+
+  // The PM gets initialized in the following, so this must occur after
+  // setting the callback.
+  Super::SetUp();
+}
+
 void PerformanceManagerBrowserTestHarness::PreRunTestOnMainThread() {
   Super::PreRunTestOnMainThread();
 
@@ -37,6 +48,8 @@ void PerformanceManagerBrowserTestHarness::SetUpCommandLine(
                                   "PerformanceManagerInstrumentation");
 }
 
+void PerformanceManagerBrowserTestHarness::OnGraphCreated(Graph* graph) {}
+
 content::Shell* PerformanceManagerBrowserTestHarness::CreateShell() {
   content::Shell* shell = CreateBrowser();
   return shell;

components/performance_manager/test_support/performance_manager_browsertest_harness.h

@@ -5,10 +5,15 @@
 #ifndef COMPONENTS_PERFORMANCE_MANAGER_TEST_SUPPORT_PERFORMANCE_MANAGER_BROWSERTEST_HARNESS_H_
 #define COMPONENTS_PERFORMANCE_MANAGER_TEST_SUPPORT_PERFORMANCE_MANAGER_BROWSERTEST_HARNESS_H_
 
+#include "base/run_loop.h"
+#include "base/test/bind_test_util.h"
+#include "components/performance_manager/public/performance_manager.h"
 #include "content/public/test/content_browser_test.h"
 
 namespace performance_manager {
 
+class Graph;
+
 // Like PerformanceManagerTestHarness, but for browser tests. Full process
 // trees and live RFHs, etc, are created. Meant to be used from
 // components_browsertests and browser_tests.
@@ -24,10 +29,17 @@ class PerformanceManagerBrowserTestHarness
       const PerformanceManagerBrowserTestHarness&) = delete;
   ~PerformanceManagerBrowserTestHarness() override;
 
+  // gtest::Test:
+  void SetUp() override;
+
   // content::BrowserTestBase:
   void PreRunTestOnMainThread() override;
   void SetUpCommandLine(base::CommandLine* command_line) override;
 
+  // An additional seam that gets invoked as part of the PM initialization. This
+  // will be invoked on the PM sequence.
+  virtual void OnGraphCreated(Graph* graph);
+
   // Creates a content shell with its own window, hosting a single tab that is
   // navigated to about:blank. The WebContents will have the PM helpers
   // attached. Ownership of the shell rests with this object. Note that such a
@@ -40,6 +52,21 @@ class PerformanceManagerBrowserTestHarness
 
   // Waits for an ongoing navigation to terminate on the given |contents|.
   void WaitForLoad(content::WebContents* contents);
+
+  // Helper function for running a task on the graph, and waiting for it to
+  // complete. The signature of OnGraphCallback is expected to be void(Graph*).
+  template <typename OnGraphCallback>
+  void RunInGraph(OnGraphCallback on_graph_callback) {
+    base::RunLoop run_loop;
+    PerformanceManager::CallOnGraph(
+        FROM_HERE,
+        base::BindLambdaForTesting([quit_loop = run_loop.QuitClosure(),
+                                    &on_graph_callback](Graph* graph) {
+          on_graph_callback(graph);
+          quit_loop.Run();
+        }));
+    run_loop.Run();
+  }
 };
 
 }  // namespace performance_manager