Change plugin and sink documents to no-quirks mode

Quirks mode layout is slower than no-quirks.

Bug: 1131185
Change-Id: Ie5421ac90e24f9e8936b431e745ffed07bbfd770
Cq-Do-Not-Cancel-Tryjobs: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424670
Commit-Queue: Nate Chapin <japhet@chromium.org>
Auto-Submit: Mason Freed <masonfreed@chromium.org>
Reviewed-by: Nate Chapin <japhet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809931}

third_party/blink/renderer/core/dom/sink_document.cc

@@ -42,7 +42,7 @@ class SinkDocumentParser : public RawDataDocumentParser {
 
 SinkDocument::SinkDocument(const DocumentInit& initializer)
     : HTMLDocument(initializer) {
-  SetCompatibilityMode(kQuirksMode);
+  SetCompatibilityMode(kNoQuirksMode);
   LockCompatibilityMode();
 }
 

third_party/blink/renderer/core/html/plugin_document.cc

@@ -186,7 +186,7 @@ PluginDocument::PluginDocument(const DocumentInit& initializer)
       background_color_(
           GetFrame()->GetPluginData()->PluginBackgroundColorForMimeType(
               initializer.GetMimeType())) {
-  SetCompatibilityMode(kQuirksMode);
+  SetCompatibilityMode(kNoQuirksMode);
   LockCompatibilityMode();
   GetExecutionContext()->GetScheduler()->RegisterStickyFeature(
       SchedulingPolicy::Feature::kContainsPlugins,