Plugin Power Saver: Refactor Plugin Instance Throttling code

content/renderer/pepper/pepper_plugin_instance_throttler_unittest.cc

Index: content/renderer/pepper/pepper_plugin_instance_throttler_unittest.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_throttler_unittest.cc b/content/renderer/pepper/pepper_plugin_instance_throttler_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e6739b65857667e195a7536b625fe911d3847da8
--- /dev/null
+++ b/content/renderer/pepper/pepper_plugin_instance_throttler_unittest.cc
@@ -0,0 +1,137 @@
+// 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/command_line.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "content/public/common/content_constants.h"
+#include "content/public/common/content_switches.h"
+#include "content/renderer/pepper/pepper_plugin_instance_throttler.h"
+#include "content/renderer/pepper/plugin_power_saver_helper.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+using testing::_;
+using testing::Return;
+
+namespace content {
+
+namespace {
+
+class MockPluginPowerSaverHelper : public PluginPowerSaverHelper {
+ public:
+  MockPluginPowerSaverHelper() : PluginPowerSaverHelper(NULL) {
+    EXPECT_CALL(*this, ShouldThrottleContent(_, _, _, _))
+        .WillRepeatedly(Return(true));
+  }
+
+  MOCK_CONST_METHOD4(ShouldThrottleContent, bool(const GURL&, int, int, bool*));
+  MOCK_METHOD2(RegisterPeripheralPlugin,
+               void(const GURL&, const base::Closure&));
+  MOCK_METHOD1(WhitelistContentOrigin, void(const GURL&));
+};
+
+}  // namespace
+
+class PepperPluginInstanceThrottlerTest : public testing::Test {
+ protected:
+  PepperPluginInstanceThrottlerTest() : change_callback_calls_(0) {}
+
+  void SetUp() override {
+    base::CommandLine::ForCurrentProcess()->AppendSwitch(
+        switches::kEnablePluginPowerSaver);
+
+    blink::WebRect rect;
+    rect.width = 100;
+    rect.height = 100;
+    throttler_.reset(new PepperPluginInstanceThrottler(
+        &power_saver_helper_, rect, kFlashPluginName,
+        GURL("http://example.com"),
+        base::Bind(&PepperPluginInstanceThrottlerTest::ChangeCallback,
+                   base::Unretained(this))));
+  }
+
+  PepperPluginInstanceThrottler* throttler() {
+    DCHECK(throttler_.get());
+    return throttler_.get();
+  }
+
+  int change_callback_calls() { return change_callback_calls_; }
+
+  void SetPluginThrottledForTest(bool throttled) {
+    throttler_->SetPluginThrottled(throttled);
+  }
+
+  void DisablePowerSaverByRetroactiveWhitelistForTest() {
+    throttler_->DisablePowerSaverByRetroactiveWhitelist();

[raymes, 2014/11/13 00:05:16]

You can avoid needing to make this public without too much trouble. The idea is
that in MockPluginPowerSaverHelper you provide an implementation of
RegisterPeripheralPlugin which just stores the callback as a local variable.
Then you can access the callback through power_saver_helper_.

[tommycli, 2014/11/13 02:33:36]

Done.

+  }
+
+ private:
+  void ChangeCallback() { ++change_callback_calls_; }
+
+  scoped_ptr<PepperPluginInstanceThrottler> throttler_;
+  MockPluginPowerSaverHelper power_saver_helper_;
+
+  int change_callback_calls_;
+
+  base::MessageLoop loop_;
+};
+
+TEST_F(PepperPluginInstanceThrottlerTest, ThrottleAndUnthrottle) {
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(0, change_callback_calls());
+
+  SetPluginThrottledForTest(true);

[raymes, 2014/11/13 00:05:16]

Rather than calling SetPluginThrottledForTest(true) another option is to use a
RunLoop to pump the message loop and simulate the real behavior. But it's a bit
of work to do and I don't want to hold this up on it.

[tommycli, 2014/11/13 02:33:36]

The current 'real' behavior is to simply wait 5 seconds, then engage the
throttle. That's so lame as to not worth be testing imo.

The next CL (coming soon) will add a luma histogram based frame inspecting
heuristic. If it's okay with you, we can add a more legit test then?

+  EXPECT_TRUE(throttler()->is_throttled());
+  EXPECT_EQ(1, change_callback_calls());
+
+  SetPluginThrottledForTest(false);

[raymes, 2014/11/13 00:05:16]

Can we use ConsumeInputEvent here instead?

[tommycli, 2014/11/13 02:33:36]

Done. I consolidated this with UnthrottleByClick now, since it now becomes the
same test.

+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(2, change_callback_calls());
+}
+
+TEST_F(PepperPluginInstanceThrottlerTest, FastWhitelisting) {
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(0, change_callback_calls());
+
+  DisablePowerSaverByRetroactiveWhitelistForTest();
+
+  SetPluginThrottledForTest(true);
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(1, change_callback_calls());
+}
+
+TEST_F(PepperPluginInstanceThrottlerTest, SlowWhitelisting) {
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(0, change_callback_calls());
+
+  SetPluginThrottledForTest(true);
+  EXPECT_TRUE(throttler()->is_throttled());
+  EXPECT_EQ(1, change_callback_calls());
+
+  DisablePowerSaverByRetroactiveWhitelistForTest();
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(2, change_callback_calls());
+}
+
+TEST_F(PepperPluginInstanceThrottlerTest, UnthrottleByClick) {
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(0, change_callback_calls());
+
+  SetPluginThrottledForTest(true);
+  EXPECT_TRUE(throttler()->is_throttled());
+  EXPECT_EQ(1, change_callback_calls());
+
+  blink::WebMouseEvent event;
+  event.type = blink::WebInputEvent::Type::MouseUp;
+  EXPECT_TRUE(throttler()->ConsumeInputEvent(event));

[raymes, 2014/11/13 00:05:16]

A few more tests for ConumeInputEvent could be good:
1) Trying to unthrottle with any event other than a click doesn't unthrottle and
consumes the event
2) Trying to unthrottle with a click if the plugin is a) already unthrottled or
b) peripheral doesn't do anything and doesn't consume the event.

[tommycli, 2014/11/13 02:33:36]

Done. Added a few more tests. Actually this caught a bug :)

+
+  EXPECT_FALSE(throttler()->is_throttled());
+  EXPECT_EQ(2, change_callback_calls());
+}
+
+}  // namespace content