Add histograms for parseAuthorStyleSheet and updateStyle

third_party/WebKit/Source/core/css/StyleSheetContents.cpp

Index: third_party/WebKit/Source/core/css/StyleSheetContents.cpp
diff --git a/third_party/WebKit/Source/core/css/StyleSheetContents.cpp b/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
index 9ad890082c3cc4b20fc52366b5317ba5fd16ad06..68cec61ada95569c4ac298112bc05b24bdf593b8 100644
--- a/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
+++ b/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
@@ -32,6 +32,7 @@
 #include "core/fetch/CSSStyleSheetResource.h"
 #include "core/frame/UseCounter.h"
 #include "core/inspector/InspectorTraceEvents.h"
+#include "platform/Histogram.h"
 #include "platform/TraceEvent.h"
 #include "platform/weborigin/SecurityOrigin.h"
 
@@ -319,6 +320,7 @@ const AtomicString& StyleSheetContents::namespaceURIFromPrefix(const AtomicStrin
 void StyleSheetContents::parseAuthorStyleSheet(const CSSStyleSheetResource* cachedStyleSheet, const SecurityOrigin* securityOrigin)
 {
     TRACE_EVENT1("blink,devtools.timeline", "ParseAuthorStyleSheet", "data", InspectorParseAuthorStyleSheetEvent::data(cachedStyleSheet));
+    SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Style.AuthorStyleSheet.ParseTime");
 
     bool isSameOriginRequest = securityOrigin && securityOrigin->canRequest(baseURL());