Remove duplicated WebGL layout tests.

third_party/WebKit/LayoutTests/SlowTests

Index: third_party/WebKit/LayoutTests/SlowTests
diff --git a/third_party/WebKit/LayoutTests/SlowTests b/third_party/WebKit/LayoutTests/SlowTests
index 522b0f5b70813b07b2708dba360a7117815099b8..0290774b7e199ef4145207347ab76ab10028a05b 100644
--- a/third_party/WebKit/LayoutTests/SlowTests
+++ b/third_party/WebKit/LayoutTests/SlowTests
@@ -11,8 +11,6 @@ crbug.com/24182 [ Debug ] storage/indexeddb/objectstore-cursor.html [ Slow ]
 crbug.com/24182 storage/indexeddb/mozilla/test_objectStore_openKeyCursor.html [ Slow ]
 crbug.com/24182 editing/selection/move-by-word-visually-mac.html [ Slow ]
 crbug.com/24182 editing/selection/move-by-word-visually-multi-line.html [ Slow ]
-crbug.com/24182 [ Win ] virtual/gpu/fast/canvas/webgl/canvas-test.html [ Slow ]
-crbug.com/24182 [ Win ] virtual/gpu/fast/canvas/webgl/framebuffer-object-attachment.html [ Slow ]
 crbug.com/24182 compositing/culling/filter-occlusion-blur-large.html [ Slow ]
 crbug.com/24182 compositing/video-frame-size-change.html [ Slow ]
 crbug.com/24182 css3/filters/effect-reference-hidpi-hw.html [ Slow ]
@@ -22,7 +20,6 @@ crbug.com/24182 editing/selection/move-by-word-visually-single-space-inline-elem
 crbug.com/24182 editing/selection/move-by-word-visually-inline-block-positioned-element.html [ Slow ]
 crbug.com/24182 editing/selection/move-by-word-visually-multi-space.html [ Slow ]
 crbug.com/24182 editing/selection/move-by-word-visually-crash-test-5.html [ Slow ]
-crbug.com/24182 fast/canvas/webgl/read-pixels-test.html [ Slow ]
 crbug.com/24182 fast/dom/SelectorAPI/resig-SelectorsAPI-test.xhtml [ Slow ]
 crbug.com/24182 fast/forms/time-multiple-fields/time-multiple-fields-stepup-stepdown-from-renderer.html [ Slow ]
 crbug.com/24182 fast/frames/cached-frame-counter.html [ Slow ]
@@ -69,7 +66,6 @@ crbug.com/24182 virtual/gpu/fast/canvas/canvas-strokePath-gradient-shadow.html [
 crbug.com/24182 virtual/gpu/fast/canvas/canvas-strokeRect-gradient-shadow.html [ Slow ]
 crbug.com/24182 virtual/gpu/fast/canvas/canvas-toDataURL-jpeg-crash.html [ Slow ]
 crbug.com/24182 virtual/gpu/fast/canvas/getPutImageDataPairTest.html [ Slow ]
-crbug.com/24182 virtual/gpu/fast/canvas/webgl/read-pixels-test.html [ Slow ]
 crbug.com/24182 fast/dom/timer-throttling-background-page-near-alignment-interval.html [ Slow ]
 crbug.com/24182 http/tests/perf/large-inlined-script.html [ Slow ]
 crbug.com/451577 [ Debug ] fast/dom/gc-treescope.html  [ Slow ]