Create entry to PWSharing through ShareHelper

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 59da207c380fc442daa56b130b79798f9253e337..02615dfbd794e4c07ea33d6f1d223b948106bc37 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -616,6 +616,24 @@ by a child template that "extends" this file.
             </intent-filter>
         </activity>
 
+        <!-- This activity is to expose the PhysicalWeb Share option via the generic Android share action. -->
+        <activity
+            android:name="org.chromium.chrome.browser.physicalweb.PhysicalWebShareActivity"
+            android:icon="@drawable/physical_web_notification_large"
+            android:label="@string/physical_web_share_activity_title"
+            android:enabled="false"
+            android:excludeFromRecents="true"
+            android:exported="true"

[cco3, 2017/01/31 01:32:57]

exported?  Do we need this?  Other apps shouldn't be using it, at least not yet.

+            android:noHistory="true"
+            android:theme="@android:style/Theme.NoDisplay"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize" >
+            <intent-filter>
+                <action android:name="android.intent.action.SEND" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="text/plain" />
+            </intent-filter>
+        </activity>
+
         <!-- Activity for dispatching intents to Instant Apps. -->
         <activity
             android:name="org.chromium.chrome.browser.instantapps.AuthenticatedProxyActivity"