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..5c77580647fe8390bb504fc9c73663df0f32080e 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
@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.tab;
 
 import android.content.Context;
 import android.graphics.Color;
+import android.support.annotation.IntDef;
 import android.view.View;
 
 import org.chromium.base.ActivityState;
@@ -44,6 +45,20 @@ 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.
+    @IntDef({TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_FOREGROUND_APP,
+        TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_BACKGROUND_APP,
+        TAB_RENDERER_EXIT_STATUS_NOT_PROTECTED_IN_FOREGROUND_APP,
+        TAB_RENDERER_EXIT_STATUS_NOT_PROTECTED_IN_BACKGROUND_APP,
+        TAB_RENDERER_EXIT_STATUS_MAX})
+    private @interface TabRendererExitStatus {}
+    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 +107,25 @@ 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.hasVisibleActivities();

[Yaron, 2015/11/19 18:57:05]

please move up to when activityState is captured

[Peter Wen, 2015/11/19 19:48:14]

Done.

+        @TabRendererExitStatus int rendererExitStatus = TAB_RENDERER_EXIT_STATUS_MAX;
+        if (processWasOomProtected) {
+            if (applicationInForeground) {
+                rendererExitStatus = TAB_RENDERER_EXIT_STATUS_OOM_PROTECTED_IN_FOREGROUND_APP;

[Yaron, 2015/11/19 18:57:05]

per discussion - can we split this out to visible vs paused

[Peter Wen, 2015/11/19 19:48:14]

Done.

+            } 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();