[CompositeClipPathAnimations]Fall back to main thread if clip-path animation is not compositable

Integrate fall back logic implemented for composited background-color
animations in

https://chromium-review.googlesource.com/c/chromium/src/+/2588636

Bug: 1245361
Change-Id: I0fa917330a83b1b3e7d14bbfa9efd23a846eb851
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3133755
Commit-Queue: Olga Gerchikov <gerchiko@microsoft.com>
Reviewed-by: Xida Chen <xidachen@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/main@{#918328}
diff --git a/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes1.html b/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes1.html
index 768f6d8..88c6862 100644
--- a/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes1.html
+++ b/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes1.html
@@ -8,7 +8,6 @@
   width: 100px;
   height: 100px;
   background-color: green;
-  clip-path: ellipse(50% 40% at 50% 50%);
   /* Use a long animation that start at 30% progress where the slope of the
      selected timing function is zero. By setting up the animation in this way,
      we accommodate lengthy delays in running the test without a potential drift
diff --git a/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes2.html b/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes2.html
index 1a4cd55..f2aa496 100644
--- a/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes2.html
+++ b/css/css-masking/clip-path/animations/clip-path-animation-incompatible-shapes2.html
@@ -8,7 +8,6 @@
   width: 300px;
   height: 300px;
   background-color: green;
-  clip-path: ellipse(50% 40% at 50% 50%);
   /* Use a long animation that start at 60% progress where the slope of the
      selected timing function is zero. By setting up the animation in this way,
      we accommodate lengthy delays in running the test without a potential drift
diff --git a/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes1.html b/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes1.html
index 00d4f2d..61e24e6 100644
--- a/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes1.html
+++ b/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes1.html
@@ -7,7 +7,6 @@
   width: 100px;
   height: 100px;
   background-color: green;
-  clip-path: ellipse(50% 40% at 50% 50%);
   /* Use a long animation that start at 5% progress where the slope of the
      selected timing function is zero. By setting up the animation in this way,
      we accommodate lengthy delays in running the test without a potential drift
diff --git a/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes2.html b/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes2.html
index 4587e4d..b70c136 100644
--- a/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes2.html
+++ b/css/css-masking/clip-path/animations/clip-path-animation-three-keyframes2.html
@@ -8,7 +8,6 @@
   width: 300px;
   height: 300px;
   background-color: green;
-  clip-path: ellipse(50% 40% at 50% 50%);
   /* Use a long animation that start at 50% progress where the slope of the
      selected timing function is zero. By setting up the animation in this way,
      we accommodate lengthy delays in running the test without a potential drift
diff --git a/css/css-masking/clip-path/animations/clip-path-animation.html b/css/css-masking/clip-path/animations/clip-path-animation.html
index 73466ba..cea2ebc 100644
--- a/css/css-masking/clip-path/animations/clip-path-animation.html
+++ b/css/css-masking/clip-path/animations/clip-path-animation.html
@@ -7,7 +7,6 @@
   width: 100px;
   height: 100px;
   background-color: green;
-  clip-path: ellipse(50% 40% at 50% 50%);
   /* Use a long animation that start at 50% progress where the slope of the
      selected timing function is zero. By setting up the animation in this way,
      we accommodate lengthy delays in running the test without a potential drift