Photo Picker Toolbar: Add UI controls showing which tile is selected.

chrome/android/java/res/layout/photo_picker_bitmap_view.xml

Index: chrome/android/java/res/layout/photo_picker_bitmap_view.xml
diff --git a/chrome/android/java/res/layout/photo_picker_bitmap_view.xml b/chrome/android/java/res/layout/photo_picker_bitmap_view.xml
index 01b0b6fd7b563eaeedce43115e2909520c5f79d1..01718226172e79a6f466476dfbc2bca3bfa3b850 100644
--- a/chrome/android/java/res/layout/photo_picker_bitmap_view.xml
+++ b/chrome/android/java/res/layout/photo_picker_bitmap_view.xml
@@ -10,8 +10,7 @@
 <view class="org.chromium.chrome.browser.photo_picker.PickerBitmapView"
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="wrap_content"
-    android:layout_height="wrap_content"
-    android:background="@color/photo_picker_tile_bg_color">

[Finnur, 2017/04/10 11:45:16]

Not needed. Will be set programmatically instead.

+    android:layout_height="wrap_content">
 
     <FrameLayout
         android:id="@+id/border"
@@ -24,8 +23,34 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:contentDescription="@null" />
+
+        <View
+            android:id="@+id/scrim"
+            android:layout_width="64dp"
+            android:layout_height="64dp"
+            android:background="@drawable/file_picker_scrim"
+            android:visibility="gone" />
     </FrameLayout>
 
+    <ImageView
+        android:id="@+id/selected"
+        android:layout_width="24dp"
+        android:layout_height="24dp"
+        android:layout_marginStart="4dp"
+        android:layout_marginTop="4dp"
+        android:contentDescription="@null"
+        android:src="@drawable/verify_checkmark"
+        android:visibility="gone" />
+
+    <View
+        android:id="@+id/unselected"
+        android:layout_width="22dp"
+        android:layout_height="22dp"
+        android:layout_marginStart="4dp"
+        android:layout_marginTop="4dp"
+        android:background="@drawable/circle_white"
+        android:visibility="gone" />
+
     <!-- Special tiles, that give access to the camera and gallery  -->
     <TextView
         android:id="@+id/special_tile"