Update TestExpectations for failing LayoutTests.

third_party/WebKit/LayoutTests/TestExpectations

Index: third_party/WebKit/LayoutTests/TestExpectations
diff --git a/third_party/WebKit/LayoutTests/TestExpectations b/third_party/WebKit/LayoutTests/TestExpectations
index 904598039756c4439998089e89f81e1c0b1d46e3..115f4694f0b7293f9a9fd0c953dbea77361dace4 100644
--- a/third_party/WebKit/LayoutTests/TestExpectations
+++ b/third_party/WebKit/LayoutTests/TestExpectations
@@ -3338,6 +3338,16 @@ crbug.com/714862 [ Android ] tables/mozilla/collapsing_borders/bug41262-3.html [
 # Sheriff failure 2017-05-05
 crbug.com/703533 [ Mac ] shapedetection/detection-security-test.html  [ Crash Pass Timeout ]
 
+# Sheriff failures 2017-05-11
+crbug.com/720511 [ Linux ] http/tests/misc/non-utf8-header-name.php [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] http/tests/security/contentSecurityPolicy/directive-parsing-03.html [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] http/tests/security/contentSecurityPolicy/source-list-parsing-04.html [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] http/tests/security/document-domain-canonicalizes.html [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] virtual/mojo-loading/http/tests/misc/non-utf8-header-name.php [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] virtual/mojo-loading/http/tests/security/contentSecurityPolicy/directive-parsing-03.html [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] virtual/mojo-loading/http/tests/security/contentSecurityPolicy/source-list-parsing-04.html [ Failure Pass Timeout ]
+crbug.com/720511 [ Linux ] virtual/mojo-loading/http/tests/security/document-domain-canonicalizes.html [ Failure Pass Timeout ]
+
 # Tests to be run only under virtual/experimental-canvas-features/
 crbug.com/682753 fast/canvas-experimental [ Skip ]