cc: Make PictureLayerImpl use a better choice for animated raster scale.

cc/animation/keyframed_animation_curve_unittest.cc

 // Copyright 2012 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 "cc/animation/keyframed_animation_curve.h"
 
 #include "cc/animation/transform_operations.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/animation/tween.h"
@@ skipping 492 matching lines @@
   EXPECT_FALSE(curve->IsTranslation());
 
   TransformOperations operations4;
   operations3.AppendTranslate(2.f, 2.f, 2.f);
   curve->AddKeyframe(TransformKeyframe::Create(
       3.0, operations4, scoped_ptr<TimingFunction>()));
 
   EXPECT_FALSE(curve->IsTranslation());
 }
 
-// Tests that maximum scale is computed as expected.
-TEST(KeyframedAnimationCurveTest, MaximumScale) {
+// Tests that maximum target scale is computed as expected.
+TEST(KeyframedAnimationCurveTest, MaximumTargetScale) {
   scoped_ptr<KeyframedTransformAnimationCurve> curve(
       KeyframedTransformAnimationCurve::Create());
 
   TransformOperations operations1;
   curve->AddKeyframe(TransformKeyframe::Create(
       0.0, operations1, scoped_ptr<TimingFunction>()));
   operations1.AppendScale(2.f, -3.f, 1.f);
   curve->AddKeyframe(TransformKeyframe::Create(
       1.0, operations1, EaseTimingFunction::Create()));
 
   float maximum_scale = 0.f;
-  EXPECT_TRUE(curve->MaximumScale(&maximum_scale));
+  EXPECT_TRUE(curve->MaximumTargetScale(true, &maximum_scale));
   EXPECT_EQ(3.f, maximum_scale);
 
   TransformOperations operations2;
   operations2.AppendScale(6.f, 3.f, 2.f);
   curve->AddKeyframe(TransformKeyframe::Create(
       2.0, operations2, EaseTimingFunction::Create()));
 
-  EXPECT_TRUE(curve->MaximumScale(&maximum_scale));
+  EXPECT_TRUE(curve->MaximumTargetScale(true, &maximum_scale));
   EXPECT_EQ(6.f, maximum_scale);
 
   TransformOperations operations3;
   operations3.AppendRotate(1.f, 0.f, 0.f, 90.f);
   curve->AddKeyframe(TransformKeyframe::Create(
       3.0, operations3, EaseTimingFunction::Create()));
 
-  EXPECT_FALSE(curve->MaximumScale(&maximum_scale));
+  EXPECT_FALSE(curve->MaximumTargetScale(true, &maximum_scale));
+
+  // The original scale is not used in computing the max.
+  scoped_ptr<KeyframedTransformAnimationCurve> curve2(
+      KeyframedTransformAnimationCurve::Create());
+
+  TransformOperations operations4;
+  operations4.AppendScale(0.4f, 0.2f, 0.6f);
+  curve2->AddKeyframe(TransformKeyframe::Create(
+      0.0, operations4, EaseTimingFunction::Create()));
+  TransformOperations operations5;
+  operations5.AppendScale(0.5f, 0.3f, -0.8f);
+  curve2->AddKeyframe(TransformKeyframe::Create(
+      1.0, operations5, EaseTimingFunction::Create()));
+
+  EXPECT_TRUE(curve2->MaximumTargetScale(true, &maximum_scale));
+  EXPECT_EQ(0.8f, maximum_scale);
+
+  EXPECT_TRUE(curve2->MaximumTargetScale(false, &maximum_scale));
+  EXPECT_EQ(0.6f, maximum_scale);
 }
 
 // Tests that an animation with a curve timing function works as expected.
 TEST(KeyframedAnimationCurveTest, CurveTiming) {
   scoped_ptr<KeyframedFloatAnimationCurve> curve(
       KeyframedFloatAnimationCurve::Create());
   curve->AddKeyframe(
       FloatKeyframe::Create(0.0, 0.f, scoped_ptr<TimingFunction>()));
   curve->AddKeyframe(
       FloatKeyframe::Create(1.0, 1.f, scoped_ptr<TimingFunction>()));
@@ skipping 77 matching lines @@
       FloatKeyframe::Create(4.0, 9.f, scoped_ptr<TimingFunction>()));
   // Curve timing function producing outputs outside of range [0,1].
   curve->SetTimingFunction(
       CubicBezierTimingFunction::Create(0.5f, -0.5f, 0.5f, 1.5f).Pass());
   EXPECT_LE(curve->GetValue(1.f), 0.f);  // c(.25) < 0
   EXPECT_GE(curve->GetValue(3.f), 9.f);  // c(.75) > 1
 }
 
 }  // namespace
 }  // namespace cc