[task_manager] Add ARC process whitelist.

chrome/browser/task_manager/providers/arc/arc_process_filter.cc

Index: chrome/browser/task_manager/providers/arc/arc_process_filter.cc
diff --git a/chrome/browser/task_manager/providers/arc/arc_process_filter.cc b/chrome/browser/task_manager/providers/arc/arc_process_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c7e3bc726776742cdcfacbc35a4f0143c2ca71a7
--- /dev/null
+++ b/chrome/browser/task_manager/providers/arc/arc_process_filter.cc
@@ -0,0 +1,49 @@
+// Copyright 2017 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 "chrome/browser/task_manager/providers/arc/arc_process_filter.h"
+
+#include <utility>
+
+#include "components/arc/common/process.mojom.h"
+
+namespace task_manager {
+
+namespace {
+
+const char* kDefaultWhitelist[] = {"/system/bin/surfaceflinger"};
+
+}  // namespace
+
+ArcProcessFilter::ArcProcessFilter()
+    : whitelist_(std::begin(kDefaultWhitelist), std::end(kDefaultWhitelist)) {}
+
+ArcProcessFilter::ArcProcessFilter(const std::set<std::string>& whitelist)
+    : whitelist_(whitelist) {}
+
+ArcProcessFilter::~ArcProcessFilter() = default;
+
+bool ArcProcessFilter::ShouldDisplayProcess(
+    const arc::ArcProcess& process) const {
+  // Check the explicit whitelist. If it is not in there, decide based on its
+  // ProcessState.
+  if (whitelist_.count(process.process_name()))
+    return true;
+  // Implicitly whitelist processes that might be important to the user.
+  // See process.mojom.
+  // ProcessState::TOP: Process is hosting the current top activities
+  // ProcessState::IMPORTANT_FOREGROUND: Process is important to the user
+  // ProcessState::TOP_SLEEPING: Same as TOP, but while the device is sleeping
+  switch (process.process_state()) {
+    case arc::mojom::ProcessState::TOP:  // Fallthrough.
+    case arc::mojom::ProcessState::IMPORTANT_FOREGROUND:
+    case arc::mojom::ProcessState::TOP_SLEEPING:
+      return true;
+    default:
+      break;
+  }
+  return false;
+}
+
+}  // namespace task_manager