Don't animate a progress bar if it isn't animated

third_party/WebKit/Source/core/layout/LayoutProgressTest.cpp

+// 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 "core/layout/LayoutProgress.h"
+
+#include "core/HTMLNames.h"
+#include "core/html/HTMLElement.h"
+#include "core/layout/LayoutTestHelper.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace blink {
+
+class LayoutProgressTest : public RenderingTest {
+public:
+    static bool isAnimationTimerActive(const LayoutProgress* o) { return o->isAnimationTimerActive(); }
+    static bool isAnimatiing(const LayoutProgress* o) { return o->isAnimating(); }
+};
+
+TEST_F(LayoutProgressTest, AnimationScheduling)
+{
+    RenderingTest::setBodyInnerHTML("<progress id=\"progressElement\" value=0.3 max=1.0></progress>");
+    document().view()->updateAllLifecyclePhases();
+    Element* progressElement = document().getElementById(AtomicString("progressElement"));
+    LayoutProgress* layoutProgress = toLayoutProgress(progressElement->layoutObject());
+
+    // Verify that we do not schedule a timer for a determinant progress element
+    EXPECT_FALSE(LayoutProgressTest::isAnimationTimerActive(layoutProgress));
+    EXPECT_FALSE(LayoutProgressTest::isAnimatiing(layoutProgress));
+
+    progressElement->removeAttribute("value");
+    document().view()->updateAllLifecyclePhases();
+
+    // Verify that we schedule a timer for an indeterminant progress element
+    EXPECT_TRUE(LayoutProgressTest::isAnimationTimerActive(layoutProgress));
+    EXPECT_TRUE(LayoutProgressTest::isAnimatiing(layoutProgress));
+
+    progressElement->setAttribute(HTMLNames::valueAttr, "0.7");
+    document().view()->updateAllLifecyclePhases();
+
+    // Verify that we cancel the timer for a determinant progress element
+    EXPECT_FALSE(LayoutProgressTest::isAnimationTimerActive(layoutProgress));
+    EXPECT_FALSE(LayoutProgressTest::isAnimatiing(layoutProgress));
+}
+
+} // namespace blink