Plugin Power Saver: Refactor Plugin Instance Throttling code

content/renderer/pepper/pepper_plugin_instance_throttler_unittest.cc

+// Copyright 2014 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 "base/bind.h"
+#include "base/logging.h"
+#include "content/renderer/pepper/pepper_plugin_instance_throttler.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+namespace content {
+
+namespace {
+
+class TestPepperPluginInstanceThrottler : public PepperPluginInstanceThrottler {

[raymes, 2014/11/12 06:38:20]

I think we can avoid inheriting from the throttler. It looks like you mainly
just want to call some private functions. The usual pattern is to have a test
class (PepperPluginInstanceThrottlerTest) which inherits from testing::Test.
Then you make the test class a friend of the PepperPluginInstanceThrottler. 

Note that you won't be able to call directly into the private methods from
inside the TEST macros below - you may need to have helper functions which do
that.

[tommycli, 2014/11/12 21:18:14]

Done.

+ public:
+  TestPepperPluginInstanceThrottler(bool power_saver_enabled,
+                                    bool is_peripheral_content)
+      : PepperPluginInstanceThrottler(
+            base::Bind(&TestPepperPluginInstanceThrottler::ChangeCallback,
+                       base::Unretained(this)),
+            power_saver_enabled,
+            is_peripheral_content),
+        change_callback_calls_(0) {}
+
+  int change_callback_calls() { return change_callback_calls_; }
+
+  void SetPluginThrottledForTest(bool throttled) {

[tommycli, 2014/11/11 19:54:30]

This seems a bit janky. Let me know if you have a better suggestion.

[raymes, 2014/11/12 06:38:20]

Rather than calling SetPluginThrottled directly, couldn't you call
ConsumeInputEvent with a crafted input event? That would test the logic there as
well.

[tommycli, 2014/11/12 21:18:14]

ConsumeInputEvent can only unthrottle, not throttle.

+    SetPluginThrottled(throttled);
+  }
+
+  void DisablePowerSaverByRetroactiveWhitelistForTest()  {
+    DisablePowerSaverByRetroactiveWhitelist();

[raymes, 2014/11/12 06:38:20]

Similarly here, you could instead pass in a mocked version of the
PluginPowerSaverHelper which gave you control over when this callback was
called.

[tommycli, 2014/11/12 21:18:14]

The 'real' PluginPowerSaverHelper underlying the mock relies on IPC, and didn't
quite work right when I tried to use it to trigger the retroactive whitelist.

+  }
+
+ private:
+  void ChangeCallback() { ++change_callback_calls_; }
+
+  int change_callback_calls_;
+};
+
+}  // namespace
+
+TEST(PepperPluginInstanceThrottlerTest, ThrottleAndUnthrottle) {
+  TestPepperPluginInstanceThrottler throttler(true /* power_saver_enabled */,
+                                              true /* is_perpheral_content */);
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(0, throttler.change_callback_calls());
+
+  throttler.SetPluginThrottledForTest(true);
+  EXPECT_TRUE(throttler.is_throttled());
+  EXPECT_EQ(1, throttler.change_callback_calls());
+
+  throttler.SetPluginThrottledForTest(false);
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(2, throttler.change_callback_calls());
+}
+
+TEST(PepperPluginInstanceThrottlerTest, FastWhitelisting) {
+  TestPepperPluginInstanceThrottler throttler(true /* power_saver_enabled */,
+                                              true /* is_perpheral_content */);
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(0, throttler.change_callback_calls());
+
+  throttler.DisablePowerSaverByRetroactiveWhitelistForTest();
+
+  throttler.SetPluginThrottledForTest(true);
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(1, throttler.change_callback_calls());
+}
+
+TEST(PepperPluginInstanceThrottlerTest, SlowWhitelisting) {
+  TestPepperPluginInstanceThrottler throttler(true /* power_saver_enabled */,
+                                              true /* is_perpheral_content */);
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(0, throttler.change_callback_calls());
+
+  throttler.SetPluginThrottledForTest(true);
+  EXPECT_TRUE(throttler.is_throttled());
+  EXPECT_EQ(1, throttler.change_callback_calls());
+
+  throttler.DisablePowerSaverByRetroactiveWhitelistForTest();
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(2, throttler.change_callback_calls());
+}
+
+TEST(PepperPluginInstanceThrottlerTest, UnthrottleByClick) {
+  TestPepperPluginInstanceThrottler throttler(true /* power_saver_enabled */,
+                                              true /* is_perpheral_content */);
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(0, throttler.change_callback_calls());
+
+  throttler.SetPluginThrottledForTest(true);
+  EXPECT_TRUE(throttler.is_throttled());
+  EXPECT_EQ(1, throttler.change_callback_calls());
+
+  blink::WebMouseEvent event;
+  event.type = blink::WebInputEvent::Type::MouseUp;
+  EXPECT_TRUE(throttler.ConsumeInputEvent(event));
+
+  EXPECT_FALSE(throttler.is_throttled());
+  EXPECT_EQ(2, throttler.change_callback_calls());
+}
+
+}  // namespace content