[Android] spellcheck: add availability UMA.

components/spellcheck/browser/spellchecker_session_bridge_android.cc

Index: components/spellcheck/browser/spellchecker_session_bridge_android.cc
diff --git a/components/spellcheck/browser/spellchecker_session_bridge_android.cc b/components/spellcheck/browser/spellchecker_session_bridge_android.cc
index 5c2644f8ecc3c85e211fd8aa0f4081aec66651df..de8b3f92550431c85c57a54cd6b64e5ded8ba549 100644
--- a/components/spellcheck/browser/spellchecker_session_bridge_android.cc
+++ b/components/spellcheck/browser/spellchecker_session_bridge_android.cc
@@ -9,6 +9,7 @@
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
+#include "base/metrics/histogram_macros.h"
 #include "components/spellcheck/common/spellcheck_messages.h"
 #include "components/spellcheck/common/spellcheck_result.h"
 #include "content/public/browser/browser_thread.h"
@@ -17,9 +18,18 @@
 
 using base::android::JavaParamRef;
 
+namespace {
+
+void RecordAvailabilityUMA(bool spellcheck_available) {
+  UMA_HISTOGRAM_BOOLEAN("Spellcheck.Android.Available", spellcheck_available);
+}
+
+}  // namespace
+
 SpellCheckerSessionBridge::SpellCheckerSessionBridge(int render_process_id)
     : render_process_id_(render_process_id),
-      java_object_initialization_failed_(false) {}
+      java_object_initialization_failed_(false),
+      active_session_(false) {}
 
 SpellCheckerSessionBridge::~SpellCheckerSessionBridge() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
@@ -38,8 +48,13 @@ void SpellCheckerSessionBridge::RequestTextCheck(int route_id,
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   // SpellCheckerSessionBridge#create() will return null if spell checker
   // service is unavailable.
-  if (java_object_initialization_failed_)
+  if (java_object_initialization_failed_) {
+    if (!active_session_) {
+      RecordAvailabilityUMA(false);
+      active_session_ = true;
+    }
     return;
+  }
 
   // RequestTextCheck IPC arrives at the message filter before
   // ToggleSpellCheck IPC when the user focuses an input field that already
@@ -50,6 +65,10 @@ void SpellCheckerSessionBridge::RequestTextCheck(int route_id,
     java_object_.Reset(Java_SpellCheckerSessionBridge_create(
         base::android::AttachCurrentThread(),
         reinterpret_cast<intptr_t>(this)));
+    if (!active_session_) {
+      RecordAvailabilityUMA(!java_object_.is_null());
+      active_session_ = true;
+    }
     if (java_object_.is_null()) {
       java_object_initialization_failed_ = true;
       return;
@@ -114,6 +133,7 @@ void SpellCheckerSessionBridge::DisconnectSession() {
 
   active_request_.reset();
   pending_request_.reset();
+  active_session_ = false;
 
   if (!java_object_.is_null()) {
     Java_SpellCheckerSessionBridge_disconnect(