Rationalize and fix chromium android linker histogram recording.

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 87f791090b0a4cb6607e8457e33adeab1e311aeb..50ea42c5d08ba3ad0e13aa1fa4667b2745d6a0cb 100644
--- a/base/android/library_loader/library_loader_hooks.cc
+++ b/base/android/library_loader/library_loader_hooks.cc
@@ -19,8 +19,26 @@ base::AtExitManager* g_at_exit_manager = NULL;
 const char* g_library_version_number = "";
 LibraryLoadedHook* g_registration_callback = NULL;
 
+bool g_has_renderer_histogram = false;
+bool g_load_renderer_at_fixed_address_failed = false;
+
 } // namespace
 
+void RegisterChromiumAndroidLinkerRendererHistogram(

[rmcilroy, 2014/10/01 12:14:42]

nit - please move down below LibraryLoaded()

[simonb (inactive), 2014/10/02 15:15:30]

Acknowledged.

+    bool load_at_fixed_address_failed) {
+  g_has_renderer_histogram = true;
+  g_load_renderer_at_fixed_address_failed = load_at_fixed_address_failed;
+}
+
+void RecordChromiumAndroidLinkerRendererHistogram() {
+  if (g_has_renderer_histogram) {
+    UMA_HISTOGRAM_BOOLEAN(
+        "ChromiumAndroidLinker.LoadedRendererAtFixedAddressFailed",
+        g_load_renderer_at_fixed_address_failed);
+    g_has_renderer_histogram = false;

[rmcilroy, 2014/10/01 12:14:42]

Maybe call the boolean g_renderer_histogram_registered_but_not_recorded since
you are also using it to ensure you don't send the UMA more than once.

[simonb (inactive), 2014/10/02 15:15:30]

Acknowledged.  The separate boolean disappeared in a rewrite.

+  }
+}
+
 void SetLibraryLoadedHook(LibraryLoadedHook* func) {
   g_registration_callback = func;
 }
@@ -31,21 +49,23 @@ static void InitCommandLine(JNIEnv* env, jclass clazz,
 }
 
 static jboolean LibraryLoaded(JNIEnv* env, jclass clazz) {
-  if(g_registration_callback == NULL) {
+  if (g_registration_callback == NULL) {
     return true;
   }
   return g_registration_callback(env, clazz);
 }
 
-static void RecordChromiumAndroidLinkerHistogram(
+static void RecordChromiumAndroidLinkerBrowserHistograms(
     JNIEnv* env,
     jclass clazz,
-    jboolean loaded_at_fixed_address_failed,
-    jboolean is_low_memory_device) {
-  UMA_HISTOGRAM_BOOLEAN("ChromiumAndroidLinker.LoadedAtFixedAddressFailed",
-                        loaded_at_fixed_address_failed);
-  UMA_HISTOGRAM_BOOLEAN("ChromiumAndroidLinker.IsLowMemoryDevice",
-                        is_low_memory_device);
+    jboolean is_using_browser_shared_relros,
+    jboolean loaded_browser_at_fixed_address_failed) {
+  UMA_HISTOGRAM_BOOLEAN(
+      "ChromiumAndroidLinker.IsUsingBrowserSharedRelros",
+      is_using_browser_shared_relros);
+  UMA_HISTOGRAM_BOOLEAN(
+      "ChromiumAndroidLinker.LoadedBrowserAtFixedAddressFailed",
+      loaded_browser_at_fixed_address_failed);
 }
 
 void LibraryLoaderExitHook() {