[Android] Record UMA metrics after native initialization completes.

base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java

Index: base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
diff --git a/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java b/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
index 278dcfe39d1e1d4ef474c949faa762daf010416c..22ed17de9ffe1a706f151527f0ceb2e2dbfeeb22 100644
--- a/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
+++ b/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
@@ -224,7 +224,10 @@ public class LibraryLoader {
 
         // From now on, keep tracing in sync with native.
         TraceEvent.registerNativeEnabledObserver();
+    }
 
+    // Called after all native initializations are complete.
+    public static void onNativeInitializationComplete() {

[Yaron, 2014/08/12 01:23:52]

Ideally you could register for this event but I see that's only possible
currently in the internal repo. Please file a cleanup bug as this is a signal we
should have upstream

[Feng Qian, 2014/08/12 16:47:01]

Good to know the event mechanism. Filed the follow-up task:
https://code.google.com/p/chromium/issues/detail?id=402925

On 2014/08/12 01:23:52, Yaron wrote:

         // Record histogram for the Chromium linker.
         if (Linker.isUsed()) {
             nativeRecordChromiumAndroidLinkerHistogram(Linker.loadAtFixedAddressFailed(),