Hook up LeakCanary to ChromePublic.apk (behind a GN arg)

chrome/android/java/AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2015 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
 <!--
 Note: This is a jinja2 template, processed at build time into the final manifest.
 
 Blocks denoted with { % block some_name % }foo{ % endblock % } can be overridden
 by a child template that "extends" this file.
@@ skipping 697 matching lines @@
 
 
         <meta-data android:name="com.google.android.gms.version"
             android:value="@integer/google_play_services_version" />
 
         <meta-data android:name="org.chromium.content.browser.SMART_CLIP_PROVIDER"
             android:value="org.chromium.content.browser.SmartClipProvider"/>
         <meta-data android:name="org.chromium.components.service_tab_launcher.SERVICE_TAB_LAUNCHER"
                    android:value="org.chromium.chrome.browser.ChromeServiceTabLauncher" />
 
+        {% set enable_leakcanary = enable_leakcanary|default(0) %}
+        {% if enable_leakcanary == "true" %}
+        {# Entries for LeakCanary copied from (and then tweaked):
+               //third_party/leakcanary/src/leakcanary-android/src/main/AndroidManifest.xml #}
+          <service
+              android:name="com.squareup.leakcanary.internal.HeapAnalyzerService"
+              android:process=":leakcanary"
+              android:enabled="false" />
+          <activity
+              android:theme="@style/leak_canary_LeakCanary.Base"
+              android:name="com.squareup.leakcanary.internal.DisplayLeakActivity"
+              android:process=":leakcanary2"  {# Added to avoid StrictMode violations crashing the activity #}
+              android:label="@string/app_name"  {# Changed from "string/leak_canary_display_activity_label" to help distinguaish when multiple apps include leakcanary. #}
+              android:icon="@drawable/leak_canary_icon"
+              android:taskAffinity=".com.squareup.leakcanary">  {# Added leading "." for multi-app case. #}
+            <intent-filter>
+              <action android:name="android.intent.action.MAIN" />
+              <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+          </activity>
+          <service
+              android:name="com.squareup.leakcanary.DisplayLeakService"
+              android:process=":leakcanary2"  {# Added to minimize interaction with browser process. #}
+              android:enabled="false" />
+          <activity  {# This is just a toast-like overlay, so leaving in browser process #}
+              android:theme="@style/leak_canary_Theme.Transparent"
+              android:name="com.squareup.leakcanary.internal.RequestStoragePermissionActivity"
+              android:taskAffinity="com.squareup.leakcanary"
+              android:enabled="false"
+              android:icon="@drawable/leak_canary_icon"
+              android:label="@string/leak_canary_storage_permission_activity_label" />
+        {% endif %}
+
         {% block extra_application_definitions %}
 
         <!-- Media route controllers to use for remote playback (cast).
              This is here, rather than in code, since it varies between upstream and downstream,
              yet we need this list of classes in the notification service, which belongs upstream
              and doesn't run the downstream startup code. The Cast code will, for each media element,
              choose the first MediaRouteController that can play it, so the order of the list can be important.
              The most specific MediaRouteControllers should be listed first, followed by more generic ones.
              The downstream manifest replaces this block, and hence replaces the list of media route
              controllers with its own list. -->
         <meta-data android:name="org.chromium.content.browser.REMOTE_MEDIA_PLAYERS"
             android:value="org.chromium.chrome.browser.media.remote.DefaultMediaRouteController"/>
 
         {% endblock %}
     </application>
 </manifest>