Animations: Allow document animation timelines to have a playback rate

This change allows for animation timelines to have a playback rate
specified which can then be used to pause or slow down all animations
on a timeline. An inspector protocol method is also added to allow the
animation timeline playback rate to be set on all document animation
timelines associated with a page.

BUG=432368

Review URL: https://codereview.chromium.org/717003002

git-svn-id: svn://svn.chromium.org/blink/trunk@185262 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/animation/AnimationTimeline.cpp

@@ -63,6 +63,9 @@ PassRefPtrWillBeRawPtr<AnimationTimeline> AnimationTimeline::create(Document* do
 AnimationTimeline::AnimationTimeline(Document* document, PassOwnPtrWillBeRawPtr<PlatformTiming> timing)
     : m_document(document)
     , m_zeroTime(0)
+    , m_currentTimeSnapshot(0)
+    , m_rawCurrentTimeSnapshot(0)
+    , m_playbackRate(1)
 {
     if (!timing)
         m_timing = adoptPtrWillBeNoop(new AnimationTimelineTiming(this));
@@ -184,7 +187,8 @@ double AnimationTimeline::currentTimeInternal(bool& isNull)
         isNull = true;
         return std::numeric_limits<double>::quiet_NaN();
     }
-    double result = m_document->animationClock().currentTime() - zeroTime();
+    // New currentTime = currentTime when the playback rate was last changed + time delta since then * playback rate
+    double result = m_currentTimeSnapshot + (m_document->animationClock().currentTime() - m_rawCurrentTimeSnapshot - zeroTime()) * playbackRate();
     isNull = std::isnan(result);
     return result;
 }
@@ -230,6 +234,19 @@ void AnimationTimeline::setOutdatedAnimationPlayer(AnimationPlayer* player)
         m_timing->serviceOnNextFrame();
 }
 
+void AnimationTimeline::setPlaybackRate(double playbackRate)
+{
+    // FIXME: need to invalidate compositor animations
+    m_currentTimeSnapshot = currentTimeInternal();
+    m_rawCurrentTimeSnapshot = m_document->animationClock().currentTime() - zeroTime();
+    m_playbackRate = playbackRate;
+}
+
+double AnimationTimeline::playbackRate() const
+{
+    return m_playbackRate;
+}
+
 #if !ENABLE(OILPAN)
 void AnimationTimeline::detachFromDocument()
 {

third_party/WebKit/Source/core/animation/AnimationTimeline.h

@@ -91,6 +91,9 @@ public:
     void setOutdatedAnimationPlayer(AnimationPlayer*);
     bool hasOutdatedAnimationPlayer() const;
 
+    void setPlaybackRate(double);
+    double playbackRate() const;
+
     Document* document() { return m_document.get(); }
 #if !ENABLE(OILPAN)
     void detachFromDocument();
@@ -110,6 +113,10 @@ private:
     WillBeHeapHashSet<RefPtrWillBeMember<AnimationPlayer>> m_playersNeedingUpdate;
     WillBeHeapHashSet<RawPtrWillBeWeakMember<AnimationPlayer>> m_players;
 
+    double m_currentTimeSnapshot;
+    double m_rawCurrentTimeSnapshot;
+    double m_playbackRate;
+
     friend class SMILTimeContainer;
     static const double s_minimumDelay;
 

third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp

@@ -186,6 +186,92 @@ TEST_F(AnimationAnimationTimelineTest, ZeroTime)
     EXPECT_FALSE(isNull);
 }
 
+TEST_F(AnimationAnimationTimelineTest, PlaybackRateForInspectorNormal)
+{
+    timeline = AnimationTimeline::create(document.get());
+    bool isNull;
+
+    document->animationClock().updateTime(100);
+    timeline->setPlaybackRate(1.0);
+    EXPECT_EQ(100, timeline->currentTimeInternal());
+    EXPECT_EQ(100, timeline->currentTimeInternal(isNull));
+    EXPECT_FALSE(isNull);
+
+    document->animationClock().updateTime(200);
+    EXPECT_EQ(200, timeline->currentTimeInternal());
+    EXPECT_EQ(200, timeline->currentTimeInternal(isNull));
+    EXPECT_FALSE(isNull);
+}
+
+TEST_F(AnimationAnimationTimelineTest, PlaybackRateForInspectorPause)
+{
+    timeline = AnimationTimeline::create(document.get());
+    bool isNull;
+
+    document->animationClock().updateTime(100);
+    EXPECT_EQ(100, timeline->currentTimeInternal());
+    EXPECT_EQ(100, timeline->currentTimeInternal(isNull));
+    EXPECT_FALSE(isNull);
+
+    timeline->setPlaybackRate(0.0);
+    document->animationClock().updateTime(200);
+    EXPECT_EQ(100, timeline->currentTimeInternal());
+    EXPECT_EQ(100, timeline->currentTimeInternal(isNull));
+
+    timeline->setPlaybackRate(1.0);
+    document->animationClock().updateTime(400);
+    EXPECT_EQ(300, timeline->currentTimeInternal());
+    EXPECT_EQ(300, timeline->currentTimeInternal(isNull));
+
+    EXPECT_FALSE(isNull);
+}
+
+TEST_F(AnimationAnimationTimelineTest, PlaybackRateForInspectorSlow)
+{
+    timeline = AnimationTimeline::create(document.get());
+    bool isNull;
+
+    document->animationClock().updateTime(100);
+    EXPECT_EQ(100, timeline->currentTimeInternal());
+    EXPECT_EQ(100, timeline->currentTimeInternal(isNull));
+    EXPECT_FALSE(isNull);
+
+    timeline->setPlaybackRate(0.5);
+    document->animationClock().updateTime(300);
+    EXPECT_EQ(200, timeline->currentTimeInternal());
+    EXPECT_EQ(200, timeline->currentTimeInternal(isNull));
+
+    timeline->setPlaybackRate(1.0);
+    document->animationClock().updateTime(400);
+    EXPECT_EQ(300, timeline->currentTimeInternal());
+    EXPECT_EQ(300, timeline->currentTimeInternal(isNull));
+
+    EXPECT_FALSE(isNull);
+}
+
+TEST_F(AnimationAnimationTimelineTest, PlaybackRateForInspectorFast)
+{
+    timeline = AnimationTimeline::create(document.get());
+    bool isNull;
+
+    document->animationClock().updateTime(100);
+    EXPECT_EQ(100, timeline->currentTimeInternal());
+    EXPECT_EQ(100, timeline->currentTimeInternal(isNull));
+    EXPECT_FALSE(isNull);
+
+    timeline->setPlaybackRate(2);
+    document->animationClock().updateTime(300);
+    EXPECT_EQ(500, timeline->currentTimeInternal());
+    EXPECT_EQ(500, timeline->currentTimeInternal(isNull));
+
+    timeline->setPlaybackRate(1.0);
+    document->animationClock().updateTime(400);
+    EXPECT_EQ(600, timeline->currentTimeInternal());
+    EXPECT_EQ(600, timeline->currentTimeInternal(isNull));
+
+    EXPECT_FALSE(isNull);
+}
+
 TEST_F(AnimationAnimationTimelineTest, PauseForTesting)
 {
     float seekTime = 1;

third_party/WebKit/Source/core/inspector/InspectorPageAgent.cpp

@@ -36,6 +36,7 @@
 #include "bindings/core/v8/ScriptRegexp.h"
 #include "core/HTMLNames.h"
 #include "core/UserAgentStyleSheets.h"
+#include "core/animation/AnimationTimeline.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/css/resolver/ViewportStyleResolver.h"
@@ -1475,6 +1476,14 @@ void InspectorPageAgent::setShowViewportSizeOnResize(ErrorString*, bool show, co
     m_state->setBoolean(PageAgentState::showGridOnResize, asBool(showGrid));
 }
 
+void InspectorPageAgent::setAnimationsPlaybackRate(ErrorString*, double playbackRate)
+{
+    for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
+        if (frame->isLocalFrame())
+            toLocalFrame(frame)->document()->timeline().setPlaybackRate(playbackRate);
+    }
+}
+
 void InspectorPageAgent::clearEditedResourcesContent()
 {
     m_editedResourceContent.clear();

third_party/WebKit/Source/core/inspector/InspectorPageAgent.h

@@ -123,6 +123,7 @@ public:
     virtual void startScreencast(ErrorString*, const String* format, const int* quality, const int* maxWidth, const int* maxHeight) override;
     virtual void stopScreencast(ErrorString*) override;
     virtual void setShowViewportSizeOnResize(ErrorString*, bool show, const bool* showGrid) override;
+    virtual void setAnimationsPlaybackRate(ErrorString*, double playbackRate) override;
 
     // InspectorInstrumentation API
     void didClearDocumentOfWindowObject(LocalFrame*);

third_party/WebKit/Source/devtools/protocol.json

@@ -583,6 +583,14 @@
                 "description": "Shows / hides color picker",
                 "hidden": true,
                 "handlers": ["browser"]
+            },
+            {
+                "name": "setAnimationsPlaybackRate",
+                "parameters": [
+                    { "name": "playbackRate", "type": "number", "description": "Playback rate for animations on page" }
+                ],
+                "description": "Sets the playback rate of the document timeline.",
+                "hidden": true
             }
         ],
         "events": [