DevTools: remove old Timeline front-end implementation

LayoutTests/SlowTests

Index: LayoutTests/SlowTests
diff --git a/LayoutTests/SlowTests b/LayoutTests/SlowTests
index a4ff77073b643032a7d6ff6c6a2d7d1b66da09a8..3da925a2264d30ee44db2b5488a6db237101b12f 100644
--- a/LayoutTests/SlowTests
+++ b/LayoutTests/SlowTests
@@ -100,9 +100,6 @@ crbug.com/394210 [ Release ] inspector/profiler/webgl/webgl-profiler-api-changes
 crbug.com/420008 [ Release ] inspector/tracing [ Slow ]
 crbug.com/420008 [ Release ] virtual/implsidepainting/inspector/tracing [ Slow ]
 crbug.com/420008 [ Release ] virtual/deferred/inspector/tracing [ Slow ]
-crbug.com/420008 [ Release ] inspector/timeline [ Slow ]
-crbug.com/420008 [ Release ] virtual/implsidepainting/inspector/timeline [ Slow ]
-crbug.com/420008 [ Release ] virtual/deferred/inspector/timeline [ Slow ]
 crbug.com/420008 [ Release ] inspector/editor/text-editor-word-jumps.html [ Slow ]
 crbug.com/420008 [ Release ] http/tests/inspector/console-xhr-logging.html [ Slow ]
 # inspector tests below are slow on LinuxASAN
@@ -166,10 +163,6 @@ crbug.com/346259 http/tests/websocket/no-crash-on-cookie-flood.html [ Slow ]
 
 crbug.com/358313 virtual/gpu/fast/canvas/webgl/webgl-large-texture.html [ Slow ]
 
-crbug.com/298188 virtual/implsidepainting/inspector/timeline/timeline-paint.html [ Slow ]
-
-crbug.com/24182 crbug.com/318490 [ Win Linux Android ] virtual/implsidepainting/inspector/timeline/timeline-decode-resize.html [ Slow ]
-
 crbug.com/313338 inspector/sources/debugger/debugger-proto-property.html [ Slow ]
 
 crbug.com/331186 [ Debug ] css3/flexbox/position-absolute-child.html [ Slow ]