memory coordinator: Throttle background renderers on Android

content/browser/memory/memory_coordinator_unittest.cc

Index: content/browser/memory/memory_coordinator_unittest.cc
diff --git a/content/browser/memory/memory_coordinator_unittest.cc b/content/browser/memory/memory_coordinator_unittest.cc
index 6b88b852da53299e3270a24e427271821b953ef4..01cc14ce9a5cccbeb6416ece1621299299e0aff0 100644
--- a/content/browser/memory/memory_coordinator_unittest.cc
+++ b/content/browser/memory/memory_coordinator_unittest.cc
@@ -26,7 +26,7 @@ void RunUntilIdle() {
 class MockChildMemoryCoordinator : public mojom::ChildMemoryCoordinator {
  public:
   MockChildMemoryCoordinator()
-      : state_(mojom::MemoryState::UNKNOWN),
+      : state_(mojom::MemoryState::NORMAL),

[bashi, 2016/12/09 03:11:16]

I had to change the initial state to NORMAL because MemoryCoordinator::ChildInfo
is initialized with NORMAL state. SetChildMemoryState() won't call
OnStateChange() when a given state and the current state are the same. It means
that the first call of SetChildMemoryState(NORMAL) doesn't change |state_| and
it remains UNKNOWN, resulted in unexpected behavior.

         on_state_change_calls_(0) {}
 
   ~MockChildMemoryCoordinator() override {}
@@ -138,4 +138,33 @@ TEST_F(MemoryCoordinatorTest, SetMemoryStateDelivered) {
   EXPECT_EQ(mojom::MemoryState::THROTTLED, cmc2->state());
 }
 
+TEST_F(MemoryCoordinatorTest, SetChildMemoryState) {
+  TestMemoryCoordinator mc;
+  auto cmc = mc.CreateChildMemoryCoordinator(1);
+  auto iter = mc.children().find(1);
+  ASSERT_TRUE(iter != mc.children().end());
+
+  // Foreground
+  iter->second.is_visible = true;
+  EXPECT_TRUE(mc.SetChildMemoryState(1, mojom::MemoryState::NORMAL));
+  EXPECT_EQ(mojom::MemoryState::NORMAL, cmc->state());
+  EXPECT_TRUE(mc.SetChildMemoryState(1, mojom::MemoryState::THROTTLED));
+  EXPECT_EQ(mojom::MemoryState::THROTTLED, cmc->state());
+  EXPECT_TRUE(mc.SetChildMemoryState(1, mojom::MemoryState::SUSPENDED));
+  EXPECT_EQ(mojom::MemoryState::THROTTLED, cmc->state());
+
+  // Background
+  iter->second.is_visible = false;
+  EXPECT_TRUE(mc.SetChildMemoryState(1, mojom::MemoryState::NORMAL));
+#if defined(OS_ANDROID)
+  EXPECT_EQ(mojom::MemoryState::THROTTLED, cmc->state());
+#else
+  EXPECT_EQ(mojom::MemoryState::NORMAL, cmc->state());
+#endif
+  EXPECT_TRUE(mc.SetChildMemoryState(1, mojom::MemoryState::THROTTLED));
+  EXPECT_EQ(mojom::MemoryState::THROTTLED, cmc->state());
+  EXPECT_TRUE(mc.SetChildMemoryState(1, mojom::MemoryState::SUSPENDED));
+  EXPECT_EQ(mojom::MemoryState::SUSPENDED, cmc->state());
+}
+
 }  // namespace content