Android Chromoting: Remove title and add navigation button to disconnect

BUG=430328

Review URL: https://codereview.chromium.org/943103002

Cr-Commit-Position: refs/heads/master@{#317489}
(cherry picked from commit 01f8886)

Review URL: https://codereview.chromium.org/955843002

Cr-Commit-Position: refs/branch-heads/2311@{#22}
Cr-Branched-From: 09b7de5-refs/heads/master@{#317474}

remoting/android/java/AndroidManifest.xml.jinja2

@@ -37,6 +37,7 @@
         </activity>
         <activity android:name="org.chromium.chromoting.Desktop"
                 android:configChanges="orientation|screenSize"
+                android:theme="@style/BaseTheme.Desktop"
                 android:windowSoftInputMode="adjustResize"/>
         <activity android:name="org.chromium.chromoting.HelpActivity"
                 android:configChanges="orientation|screenSize"

remoting/android/java/res/values-v17/styles.xml

@@ -14,6 +14,13 @@
         <item name="windowActionBar">false</item>
         <item name="android:windowDrawsSystemBarBackgrounds">true</item>
     </style>
+    <style name="BaseTheme.Desktop" parent="@style/BaseTheme">
+        <item name="actionBarStyle">@style/ActionBar.Desktop</item>
+    </style>
+
+    <style name="ActionBar.Desktop" parent="@style/Widget.AppCompat.ActionBar">
+        <item name="displayOptions">homeAsUp</item>
+    </style>
 
     <style name="EmptyStateText" parent="@android:style/TextAppearance.Large">
         <item name="android:textColor">#888</item>

remoting/android/java/src/org/chromium/chromoting/Desktop.java

@@ -51,7 +51,11 @@ public void onCreate(Bundle savedInstanceState) {
         mOverlayButton = (ImageButton) findViewById(R.id.desktop_overlay_button);
         mRemoteHostDesktop.setDesktop(this);
 
-        // Ensure the button is initially hidden.
+        // For this Activity, the home button in the action bar acts as a Disconnect button, so
+        // set the description for accessibility/screen readers.
+        getSupportActionBar().setHomeActionContentDescription(R.string.disconnect_myself_button);
+
+        // Ensure the overlay button is initially hidden.
         showActionBar();
 
         View decorView = getWindow().getDecorView();
@@ -193,7 +197,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
             hideActionBar();
             return true;
         }
-        if (id == R.id.actionbar_disconnect) {
+        if (id == R.id.actionbar_disconnect || id == android.R.id.home) {
             JniInterface.disconnectFromHost();
             return true;
         }