Record the return value of NativeLibraryPreloader.loadLibrary in UMA

base/android/library_loader/library_loader_hooks.cc

Index: base/android/library_loader/library_loader_hooks.cc
diff --git a/base/android/library_loader/library_loader_hooks.cc b/base/android/library_loader/library_loader_hooks.cc
index bbc99352f6d8211146574ca3025328de0bfcbbaf..6e9cb832b6fed8fd95015e559a547d4567b00fe7 100644
--- a/base/android/library_loader/library_loader_hooks.cc
+++ b/base/android/library_loader/library_loader_hooks.cc
@@ -10,6 +10,7 @@
 #include "base/android/library_loader/library_prefetcher.h"
 #include "base/at_exit.h"
 #include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
 #include "jni/LibraryLoader_jni.h"
 
 namespace base {
@@ -48,6 +49,12 @@ enum BrowserHistogramCode {
 
 RendererHistogramCode g_renderer_histogram_code = NO_PENDING_HISTOGRAM_CODE;
 
+// Indicate whether g_library_preloader_renderer_histogram_code is valid
+bool g_library_preloader_renderer_histogram_code_registered = false;
+
+// The return value of NativeLibraryPreloader.loadLibrary() in child processes.
+int g_library_preloader_renderer_histogram_code = 0;
+
 // The amount of time, in milliseconds, that it took to load the shared
 // libraries in the renderer. Set in
 // RegisterChromiumAndroidLinkerRendererHistogram.
@@ -72,7 +79,7 @@ static void RegisterChromiumAndroidLinkerRendererHistogram(
   g_renderer_library_load_time_ms = library_load_time_ms;
 }
 
-void RecordChromiumAndroidLinkerRendererHistogram() {
+static void RecordChromiumAndroidLinkerRendererHistogram() {

[Alexei Svitkine (slow), 2016/05/26 19:14:11]

If you only call it locally in the file, put it in the anon namespace above
instead. Also, seems like you can simplify this function name as well.

[michaelbai, 2016/05/26 19:38:51]

Moved to anon namespace, but the name is correct.

   if (g_renderer_histogram_code == NO_PENDING_HISTOGRAM_CODE)
     return;
   // Record and release the pending histogram value.
@@ -116,6 +123,36 @@ static void RecordChromiumAndroidLinkerBrowserHistogram(
                       base::TimeDelta::FromMilliseconds(library_load_time_ms));
 }
 
+static void RecordLibraryPreloaderBrowserHistogram(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& jcaller,
+    jint status) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY(
+      "Android.NativeLibraryPreloader.Result.Browser",
+      status);
+}
+
+static void RegisterLibraryPreloaderRendererHistogram(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& jcaller,
+    jint status) {
+  g_library_preloader_renderer_histogram_code = status;
+  g_library_preloader_renderer_histogram_code_registered = true;
+}
+
+static void RecordLibraryPreloaderRendereHistogram() {

[Alexei Svitkine (slow), 2016/05/26 19:14:11]

Put this in the anon namespace above.

[michaelbai, 2016/05/26 19:38:51]

Moved to anon namespace.

+  if (g_library_preloader_renderer_histogram_code_registered) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY(
+        "Android.NativeLibraryPreloader.Result.Renderer",
+        g_library_preloader_renderer_histogram_code);
+  }
+}
+
+void RecordLibraryLoaderRendererHistogram() {

[Alexei Svitkine (slow), 2016/05/26 19:14:11]

This is recording multiple histograms right? Make the name plural.

[michaelbai, 2016/05/26 19:38:51]

Done.

+  RecordChromiumAndroidLinkerRendererHistogram();
+  RecordLibraryPreloaderRendereHistogram();
+}
+
 void SetLibraryLoadedHook(LibraryLoadedHook* func) {
   g_registration_callback = func;
 }