Add Rounded Corners to snackbars on Tablet

Per Material Design, floating snackbars should have rounded corners with
radius of 2dp. This CL implements this detail.

BUG=545258
R=dfalcantara@chromium.org

Review URL: https://codereview.chromium.org/1414423002 .

Cr-Commit-Position: refs/heads/master@{#355424}

chrome/android/java/res/drawable-sw600dp/snackbar_background.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2015 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle" >
+
+    <solid android:color="@color/snackbar_background_color" />
+
+    <corners android:radius="2dip" />
+
+</shape>

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

@@ -6,7 +6,6 @@
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:background="#282C32"
     android:minHeight="@dimen/snackbar_min_height"
     android:orientation="horizontal" >
 

chrome/android/java/res/values/colors.xml

@@ -21,6 +21,9 @@
     <color name="infobar_accent_blue">#4285f4</color>
     <color name="infobar_tertiary_button_text">#969696</color>
 
+    <!-- Snackbar colors -->
+    <color name="snackbar_background_color">#282C32</color>
+
     <!-- Tab Switcher Colors -->
     <color name="tab_switcher_background">#14181C</color>
     <color name="accessibility_tab_switcher_list_item">#252525</color>

chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarPopupWindow.java

@@ -4,13 +4,15 @@
 
 package org.chromium.chrome.browser.snackbar;
 
+import android.graphics.drawable.GradientDrawable;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.PopupWindow;
 import android.widget.TextView;
 
+import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.chrome.R;
 import org.chromium.ui.base.DeviceFormFactor;
 
@@ -67,8 +69,23 @@ void update(Snackbar snackbar, boolean animate) {
         mMessageView.setTemplate(snackbar.getTemplateText());
         setViewText(mMessageView, snackbar.getText(), animate);
         String actionText = snackbar.getActionText();
+
+        View view = getContentView();
+        int backgroundColor = snackbar.getBackgroundColor();
+        if (backgroundColor == 0) {
+            backgroundColor = ApiCompatibilityUtils.getColor(view.getResources(),
+                    R.color.snackbar_background_color);
+        }
+
+        if (DeviceFormFactor.isTablet(view.getContext())) {
+            // On tablet, snackbar popups have rounded corners.
+            view.setBackgroundResource(R.drawable.snackbar_background);
+            ((GradientDrawable) view.getBackground()).setColor(backgroundColor);
+        } else {
+            view.setBackgroundColor(backgroundColor);
+        }
+
         if (snackbar.getBackgroundColor() != 0) {
-            View view = getContentView();
             view.setBackgroundColor(snackbar.getBackgroundColor());
         }
         if (actionText != null) {