Enable account-switcher to render into the status-bar.

Added android:fitsSystemWindows attribute to the navigation drawer
(attribute was already set in containing window, but also needed here).
Made the status-bar transparent so the navigation-drawer can render into
it.
Added a method to the AccountSwitcher interface, so the Google
implementation can apply the correct level of overlap.

BUG=517688

Review URL: https://codereview.chromium.org/1395683002

Cr-Commit-Position: refs/heads/master@{#353228}

remoting/android/java/res/layout/main.xml

@@ -71,6 +71,7 @@
         android:layout_height="match_parent"
         android:orientation="vertical"
         android:layout_gravity="start"
-        android:background="@android:color/background_light">
+        android:background="@android:color/background_light"
+        android:fitsSystemWindows="true">
     </LinearLayout>
 </android.support.v4.widget.DrawerLayout>

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

@@ -17,6 +17,11 @@
         <item name="windowNoTitle">true</item>
         <!--suppress NewApi -->
         <item name="android:windowDrawsSystemBarBackgrounds">true</item>
+        <!-- The status bar is normally fully opaque and rendered above the
+             activity. Make it fully transparent to allow the DrawerLayout to
+             control the rendering of the status bar background -->
+        <!--suppress NewApi -->
+        <item name="android:statusBarColor">@android:color/transparent</item>
     </style>
 
     <style name="EmptyStateText" parent="@android:style/TextAppearance.Large">

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

@@ -220,6 +220,7 @@ public void onItemClick(AdapterView<?> parent, View view, int position,
         mAccountSwitcher = AccountSwitcherFactory.getInstance().createAccountSwitcher(this, this);
         mAccountSwitcher.setNavigation(navigationMenu);
         LinearLayout navigationDrawer = (LinearLayout) findViewById(R.id.navigation_drawer);
+        mAccountSwitcher.setDrawer(navigationDrawer);
         View switcherView = mAccountSwitcher.getView();
         switcherView.setLayoutParams(new LinearLayout.LayoutParams(
                 LinearLayout.LayoutParams.MATCH_PARENT,

remoting/android/java/src/org/chromium/chromoting/accountswitcher/AccountSwitcher.java

@@ -46,6 +46,12 @@ public interface Callback {
      */
     void setNavigation(View view);
 
+    /**
+     * Sets the view that holds the navigation drawer. The account-switcher may register with
+     * {@link View.setOnApplyWindowInsetsListener} in order to render into the status-bar area.
+     */
+    void setDrawer(View drawerView);
+
     /**
      * Sets the user preferences for the currently-selected and most-recently-used accounts.
      * The caller is responsible for loading these preferences when the activity is started. This

remoting/android/java/src/org/chromium/chromoting/accountswitcher/AccountSwitcherBasic.java

@@ -63,6 +63,10 @@ public void setNavigation(View view) {
         mContainer.addView(view);
     }
 
+    @Override
+    public void setDrawer(View drawerView) {
+    }
+
     @Override
     public void setSelectedAndRecentAccounts(String selected, String[] recents) {
         // This implementation does not support recents.