Disable ScrollbarsTest.NativeScrollbarChangeToMobileByEmulator etc on the chromeos bot

These tests are faling on the bot.

Bug: 795645
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: If49997081c2034fea813724281bb8bf6fc3d81d3
TBR: fmalita@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/831005Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524659}

third_party/WebKit/Source/core/layout/ScrollbarsTest.cpp

@@ -978,8 +978,8 @@ TEST_P(ScrollbarsTest,
 
 // Make sure native scrollbar can change by Emulator.
 // Disable on Android since Android always enable OverlayScrollbar.
-
-#if defined(OS_ANDROID)
+// TODO(https://crbug.com/795645): This test is failing on the ChromeOS bot.
+#if defined(OS_ANDROID) || defined(OS_CHROMEOS)
 TEST_P(ScrollbarsTest, DISABLED_NativeScrollbarChangeToMobileByEmulator) {
 #else
 TEST_P(ScrollbarsTest, NativeScrollbarChangeToMobileByEmulator) {

third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp

@@ -204,7 +204,12 @@ TEST_F(PaintLayerClipperTest, RoundedClipNested) {
   EXPECT_EQ(LayoutRect(0, 0, 500, 500), layer_bounds);
 }
 
+// TODO(https://crbug.com/795645): This test is failing on the ChromeOS bot.
+#if defined(OS_CHROMEOS)
+TEST_F(PaintLayerClipperTest, DISABLED_ControlClipSelect) {
+#else
 TEST_F(PaintLayerClipperTest, ControlClipSelect) {
+#endif
   SetBodyInnerHTML(R"HTML(
     <select id='target' style='position: relative; width: 100px;
         background: none; border: none; padding: 0px 15px 0px 5px;'>