Disable WebSocket SafeBrowsing checks

As a temporary workaround for http://crbug.com/750278, disable WebSocket
SafeBrowsing checks. They will be reenabled once the bug is fixed.

Relevant browser tests are also disabled.

BUG=750278, 644744

Change-Id: I8b1e731be567ac49e60b4a02c927c6bc57d9a736
Reviewed-on: https://chromium-review.googlesource.com/594750Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491306}

chrome/browser/safe_browsing/safe_browsing_service_browsertest.cc

@@ -1490,7 +1490,7 @@ class SafeBrowsingServiceWebSocketTest
       public SafeBrowsingServiceTest {};
 
 IN_PROC_BROWSER_TEST_P(SafeBrowsingServiceWebSocketTest,
-                       MalwareWebSocketBlocked) {
+                       DISABLED_MalwareWebSocketBlocked) {
   GURL main_url = embedded_test_server()->GetURL(kMalwareWebSocketPage);
   // This constructs the URL with the same logic as malware_websocket.html.
   GURL resolved = main_url.Resolve("/safe_browsing/malware-ws");
@@ -2269,7 +2269,7 @@ class V4SafeBrowsingServiceWebSocketTest
 // SafeBrowsingServiceWebSocketTest.MalwareWebSocketBlocked. That test will be
 // deleted when the old database backend is removed.
 IN_PROC_BROWSER_TEST_P(V4SafeBrowsingServiceWebSocketTest,
-                       MalwareWebSocketBlocked) {
+                       DISABLED_MalwareWebSocketBlocked) {
   GURL main_url = embedded_test_server()->GetURL(kMalwareWebSocketPage);
   // This constructs the URL with the same logic as malware_websocket.html.
   GURL resolved = main_url.Resolve("/safe_browsing/malware-ws");

chrome/renderer/chrome_content_renderer_client.cc

@@ -1358,9 +1358,7 @@ bool ChromeContentRendererClient::IsExtensionOrSharedModuleWhitelisted(
 
 std::unique_ptr<blink::WebSocketHandshakeThrottle>
 ChromeContentRendererClient::CreateWebSocketHandshakeThrottle() {
-  InitSafeBrowsingIfNecessary();
-  return base::MakeUnique<safe_browsing::WebSocketSBHandshakeThrottle>(
-      safe_browsing_.get());
+  return nullptr;
 }
 
 std::unique_ptr<blink::WebSpeechSynthesizer>