Remove custom counts histogram from the blink API.

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

Index: third_party/WebKit/Source/core/css/FontFaceSet.cpp
diff --git a/third_party/WebKit/Source/core/css/FontFaceSet.cpp b/third_party/WebKit/Source/core/css/FontFaceSet.cpp
index 7b435591e68a841519c2bf7780fbeeffc6b40d14..89890bfdb72cef4a6605cb263d73c184ede15341 100644
--- a/third_party/WebKit/Source/core/css/FontFaceSet.cpp
+++ b/third_party/WebKit/Source/core/css/FontFaceSet.cpp
@@ -40,6 +40,7 @@
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/style/StyleInheritedData.h"
+#include "platform/Histogram.h"
 #include "public/platform/Platform.h"
 
 namespace blink {
@@ -479,7 +480,8 @@ void FontFaceSet::FontLoadHistogram::record()
 {
     if (!m_recorded) {
         m_recorded = true;
-        Platform::current()->histogramCustomCounts("WebFont.WebFontsInPage", m_count, 1, 100, 50);
+        DEFINE_THREAD_SAFE_STATIC_LOCAL(CustomCountHistogram, webFontsInPageHistogram, new CustomCountHistogram("WebFont.WebFontsInPage", 1, 100, 50));

[esprehn, 2016/02/04 23:25:23]

FontFaceSet is main thread only today, someday it might need to be thread safe,
but it isn't in general today.

+        webFontsInPageHistogram.count(m_count);
     }
     if (m_status == HadBlankText || m_status == DidNotHaveBlankText) {
         Platform::current()->histogramEnumeration("WebFont.HadBlankText", m_status == HadBlankText ? 1 : 0, 2);