[Doodle] Add UMA for doodle image downloads

chrome/browser/android/logo_bridge.cc

Index: chrome/browser/android/logo_bridge.cc
diff --git a/chrome/browser/android/logo_bridge.cc b/chrome/browser/android/logo_bridge.cc
index 347441e40b42e63e34875aeb6e961fa996cdfd48..531b0dbfc7b56d11705448360ca1428395e91c1a 100644
--- a/chrome/browser/android/logo_bridge.cc
+++ b/chrome/browser/android/logo_bridge.cc
@@ -301,6 +301,9 @@ void LogoBridge::DoodleImageFetched(
     return;
   }
 
+  UMA_HISTOGRAM_BOOLEAN("NewTabPage.LogoImageDownloaded",
+                        metadata.from_http_cache);
+
   ScopedJavaLocalRef<jobject> j_logo = MakeJavaLogo(
       env, image.ToSkBitmap(), on_click_url, alt_text, animated_image_url);
   Java_LogoObserver_onLogoAvailable(env, j_logo_observer_, j_logo,