Add stats to distinguish android renderer crashes.

chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java
index 755c9dfaf8e21153328a57674df5c1d4459da00c..3cd99b3ad8ce08f2e73e5223290d900b91dd39d3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java
@@ -44,6 +44,14 @@ public class TabWebContentsObserver extends WebContentsObserver {
     private static final int TAB_RENDERER_CRASH_STATUS_HIDDEN_IN_BACKGROUND_APP = 2;
     private static final int TAB_RENDERER_CRASH_STATUS_MAX = 3;
 
+    // TabRendererExitStatus defined in tools/metrics/histograms/histograms.xml.
+    // Designed to replace TabRendererCrashStatus if numbers line up.
+    private static final int TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_FOREGROUND_APP = 0;
+    private static final int TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_BACKGROUND_APP = 1;
+    private static final int TAB_RENDERER_EXIT_STATUS_NOT_PROTECTED_IN_FOREGROUND_APP = 2;
+    private static final int TAB_RENDERER_EXIT_STATUS_NOT_PROTECTED_IN_BACKGROUND_APP = 3;
+    private static final int TAB_RENDERER_EXIT_STATUS_MAX = 4;
+
     private final Tab mTab;
     private int mThemeColor;
 
@@ -92,6 +100,25 @@ public class TabWebContentsObserver extends WebContentsObserver {
         RecordHistogram.recordEnumeratedHistogram(
                 "Tab.RendererCrashStatus", rendererCrashStatus, TAB_RENDERER_CRASH_STATUS_MAX);
 
+        // This will replace TabRendererCrashStatus if numbers line up.
+        boolean applicationInForeground = ApplicationStatus.hasRunningActivities();
+        int rendererExitStatus = TAB_RENDERER_EXIT_STATUS_MAX;
+        if (processWasOomProtected) {
+            if (applicationInForeground) {
+                rendererExitStatus = TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_FOREGROUND_APP;
+            } else {
+                rendererExitStatus = TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_BACKGROUND_APP;
+            }
+        } else {
+            if (applicationInForeground) {
+                rendererExitStatus = TAB_RENDERER_EXIT_STATUS_NOT_PROTECTED_IN_FOREGROUND_APP;
+            } else {
+                rendererExitStatus = TAB_RENDERER_EXIT_STATUS_NOT_PROTECTED_IN_BACKGROUND_APP;
+            }
+        }
+        RecordHistogram.recordEnumeratedHistogram(
+                "Tab.RendererExitStatus", rendererExitStatus, TAB_RENDERER_EXIT_STATUS_MAX);
+
         mTab.handleTabCrash();
 
         boolean sadTabShown = mTab.isShowingSadTab();