Remove the obsolete MinidumpDirectoryObserver experiment.

This experiment is rolled out to 100% of users server-side, so:
(1) Update the client code to default to the new code path, and
(2) Remove the old code path, which is no longer reachable.

BUG=none
TEST=none
R=mlliu@chromium.org

Review-Url: https://codereview.chromium.org/2282273002
Cr-Commit-Position: refs/heads/master@{#415780}

chrome/android/java/src/org/chromium/chrome/browser/crash/MinidumpDirectoryObserver.java

@@ -24,8 +24,6 @@ public class MinidumpDirectoryObserver extends FileObserver {
     private static final String TAG = "MinidumpDirObserver";
     private static Context sContext = ContextUtils.getApplicationContext();
 
-    public static final String MINIDUMP_EXPERIMENT_NAME = "MinidumpDirectoryObserver";
-
     public MinidumpDirectoryObserver() {
         // The file observer detects MOVED_TO for child processes.
         super(new File(PathUtils.getCacheDirectory(sContext),

chrome/android/java/src/org/chromium/chrome/browser/init/ChromeBrowserInitializer.java

@@ -12,7 +12,6 @@ import android.os.Handler;
 import android.os.Looper;
 import android.os.Process;
 import android.os.StrictMode;
-import android.text.TextUtils;
 
 import com.squareup.leakcanary.LeakCanary;
 
@@ -42,7 +41,6 @@ import org.chromium.chrome.browser.services.GoogleServicesManager;
 import org.chromium.chrome.browser.tabmodel.document.DocumentTabModelImpl;
 import org.chromium.chrome.browser.webapps.ActivityAssigner;
 import org.chromium.chrome.browser.webapps.ChromeWebApkHost;
-import org.chromium.components.variations.VariationsAssociatedData;
 import org.chromium.content.app.ContentApplication;
 import org.chromium.content.browser.BrowserStartupController;
 import org.chromium.content.browser.ChildProcessCreationParams;
@@ -397,23 +395,19 @@ public class ChromeBrowserInitializer {
         mNativeInitializationComplete = true;
         ContentUriUtils.setFileProviderUtil(new FileProviderHelper());
 
-        if (TextUtils.equals("true", VariationsAssociatedData.getVariationParamValue(
-                MinidumpDirectoryObserver.MINIDUMP_EXPERIMENT_NAME, "Enabled"))) {
-
-            // Start the file observer to watch the minidump directory.
-            new AsyncTask<Void, Void, MinidumpDirectoryObserver>() {
-                @Override
-                protected MinidumpDirectoryObserver doInBackground(Void... params) {
-                    return new MinidumpDirectoryObserver();
-                }
+        // Start the file observer to watch the minidump directory.
+        new AsyncTask<Void, Void, MinidumpDirectoryObserver>() {
+            @Override
+            protected MinidumpDirectoryObserver doInBackground(Void... params) {
+                return new MinidumpDirectoryObserver();
+            }
 
-                @Override
-                protected void onPostExecute(MinidumpDirectoryObserver minidumpDirectoryObserver) {
-                    mMinidumpDirectoryObserver = minidumpDirectoryObserver;
-                    mMinidumpDirectoryObserver.startWatching();
-                }
-            }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-        }
+            @Override
+            protected void onPostExecute(MinidumpDirectoryObserver minidumpDirectoryObserver) {
+                mMinidumpDirectoryObserver = minidumpDirectoryObserver;
+                mMinidumpDirectoryObserver.startWatching();
+            }
+        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
 
     private void waitForDebuggerIfNeeded() {

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

@@ -13,7 +13,6 @@ import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.Rect;
 import android.net.Uri;
-import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
@@ -38,7 +37,6 @@ import org.chromium.base.TraceEvent;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.metrics.RecordHistogram;
-import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.blimp_public.contents.BlimpContents;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeActivity;
@@ -60,8 +58,6 @@ import org.chromium.chrome.browser.blimp.BlimpClientContextFactory;
 import org.chromium.chrome.browser.compositor.layouts.content.TabContentManager;
 import org.chromium.chrome.browser.contextmenu.ContextMenuPopulator;
 import org.chromium.chrome.browser.contextualsearch.ContextualSearchTabHelper;
-import org.chromium.chrome.browser.crash.MinidumpDirectoryObserver;
-import org.chromium.chrome.browser.crash.MinidumpUploadService;
 import org.chromium.chrome.browser.customtabs.CustomTabActivity;
 import org.chromium.chrome.browser.download.ChromeDownloadDelegate;
 import org.chromium.chrome.browser.fullscreen.FullscreenManager;
@@ -94,7 +90,6 @@ import org.chromium.chrome.browser.util.ColorUtils;
 import org.chromium.components.dom_distiller.core.DomDistillerUrlUtils;
 import org.chromium.components.navigation_interception.InterceptNavigationDelegate;
 import org.chromium.components.security_state.ConnectionSecurityLevel;
-import org.chromium.components.variations.VariationsAssociatedData;
 import org.chromium.content.browser.ActivityContentVideoViewEmbedder;
 import org.chromium.content.browser.ChildProcessLauncher;
 import org.chromium.content.browser.ContentVideoViewEmbedder;
@@ -2831,29 +2826,6 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
         mIsBeingRestored = false;
 
         if (mTabUma != null) mTabUma.onRendererCrashed();
-
-        if (!TextUtils.equals("true", VariationsAssociatedData.getVariationParamValue(
-                MinidumpDirectoryObserver.MINIDUMP_EXPERIMENT_NAME, "Enabled"))) {
-            try {
-                // Update the most recent minidump file with the logcat. Doing this asynchronously
-                // adds a race condition in the case of multiple simultaneously renderer crashses
-                // but because the data will be the same for all of them it is innocuous. We can
-                // attempt to do this regardless of whether it was a foreground tab in the event
-                // that it's a real crash and not just android killing the tab.
-                Context context = getApplicationContext();
-                Intent intent = MinidumpUploadService.createFindAndUploadLastCrashIntent(context);
-                context.startService(intent);
-                RecordUserAction.record("MobileBreakpadUploadAttempt");
-            } catch (SecurityException e) {
-                // For KitKat and below, there was a framework bug which cause us to not be able to
-                // find our own crash uploading service. Ignore a SecurityException here on older
-                // OS versions since the crash will eventually get uploaded on next start.
-                // crbug/542533
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
-                    throw e;
-                }
-            }
-        }
     }
 
     /**

testing/variations/fieldtrial_testing_config_android.json

@@ -206,14 +206,6 @@
             "group_name": "Enabled"
         }
     ],
-    "MinidumpDirectoryObserver": [
-        {
-            "group_name": "ObserverExperimentGroup",
-            "params": {
-                "Enabled": "true"
-            }
-        }
-    ],
     "ModerateBindingOnBackgroundTabCreation": [
         {
             "group_name": "Enabled"