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

chrome/android/java/AndroidManifest.xml

Index: chrome/android/java/AndroidManifest.xml
diff --git a/chrome/android/java/AndroidManifest.xml b/chrome/android/java/AndroidManifest.xml
index 914ef9ac4e4a6a168f70252cb5eae9b08d22ff46..8cdc2bf5c65f25e5e8497bd53a2c9f0ba77fd1f6 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -715,6 +715,39 @@ android:value="true" />
         <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).