[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 cd6284ace3d7a39a5f311b4dd7a6bc4191591c63..82de78ae10bd0aa5aa311c157e8d6b369282dc15 100644
--- a/chrome/browser/android/logo_bridge.cc
+++ b/chrome/browser/android/logo_bridge.cc
@@ -299,6 +299,9 @@ 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,