Add memory pressure dispatching callback to MemoryCoordinator

components/memory_coordinator/browser/memory_coordinator_unittest.cc

Index: components/memory_coordinator/browser/memory_coordinator_unittest.cc
diff --git a/components/memory_coordinator/browser/memory_coordinator_unittest.cc b/components/memory_coordinator/browser/memory_coordinator_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5fe205edb4f1a2ca7d36d4c62936ddf5a62dad41
--- /dev/null
+++ b/components/memory_coordinator/browser/memory_coordinator_unittest.cc
@@ -0,0 +1,91 @@
+// 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 "components/memory_coordinator/browser/memory_coordinator.h"
+
+#include "base/memory/memory_pressure_monitor.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace memory_coordinator {
+
+namespace {
+
+class MockMemoryPressureMonitor : public base::MemoryPressureMonitor {
+ public:
+  ~MockMemoryPressureMonitor() override {}
+
+  void Dispatch(MemoryPressureLevel level) {
+    DCHECK(!callback_.is_null());
+    callback_.Run(level);
+  }
+
+  // MemoryPressureMonitor implementations:
+  MemoryPressureLevel GetCurrentPressureLevel() const override {
+    return base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
+  }
+
+  void SetDispatchCallback(const DispatchCallback& callback) override {
+    callback_ = callback;
+  }
+
+ private:
+  DispatchCallback callback_;
+};
+
+class MockMemoryCoordinatorClient final : public MemoryCoordinatorClient {
+public:
+  void OnMemoryStateChange(mojom::MemoryState state) override {
+    last_state_ = state;
+  }
+
+  mojom::MemoryState last_state() const { return last_state_; }
+
+ private:
+  mojom::MemoryState last_state_ = mojom::MemoryState::UNKNOWN;
+};
+
+}  // namespace
+
+class MemoryCoordinatorTest : public testing::Test {
+ public:
+  MemoryCoordinatorTest() : message_loop_(new base::MessageLoop) {
+    // MemoryCoordinator needs to be initialized after an instance of
+    // MemoryPressureMonitor is created.
+    coordinator_.reset(new MemoryCoordinator);
+  }
+
+  MockMemoryPressureMonitor& monitor() { return monitor_; }
+  MemoryCoordinator& coordinator() { return *coordinator_.get(); }
+
+ private:
+  std::unique_ptr<base::MessageLoop> message_loop_;
+  MockMemoryPressureMonitor monitor_;
+  std::unique_ptr<MemoryCoordinator> coordinator_;
+};
+
+TEST_F(MemoryCoordinatorTest, ReceivePressureLevels) {
+  MockMemoryCoordinatorClient client;
+  coordinator().RegisterClient(&client);
+
+  {
+    base::RunLoop loop;
+    monitor().Dispatch(
+        base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE);
+    loop.RunUntilIdle();
+    EXPECT_EQ(mojom::MemoryState::THROTTLED, client.last_state());
+  }
+
+  {
+    base::RunLoop loop;
+    monitor().Dispatch(
+        base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
+    loop.RunUntilIdle();
+    EXPECT_EQ(mojom::MemoryState::SUSPENDED, client.last_state());
+  }
+}
+
+}  // namespace memory_coordinator