Support setting mouse cursor icon in Android N.

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java

 // 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.
 
 package org.chromium.chrome.browser.compositor;
 
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Rect;
 import android.graphics.RectF;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v4.view.ViewCompat;
 import android.support.v4.view.accessibility.AccessibilityEventCompat;
 import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
 import android.support.v4.widget.ExploreByTouchHelper;
 import android.util.AttributeSet;
 import android.util.Pair;
 import android.view.DragEvent;
 import android.view.MotionEvent;
+import android.view.PointerIcon;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.accessibility.AccessibilityEvent;
 import android.widget.FrameLayout;
 
 import org.chromium.base.SysUtils;
 import org.chromium.base.TraceEvent;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.compositor.Invalidator.Client;
@@ skipping 142 matching lines @@
     /**
      * Creates a {@link CompositorView}.
      * @param c The Context to create this {@link CompositorView} in.
      */
     public CompositorViewHolder(Context c) {
         super(c);
 
         internalInit();
     }
 
+    @Override
+    public PointerIcon onResolvePointerIcon(MotionEvent event, int pointerIndex) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) return null;
+        ContentViewCore content = getActiveContent();

[Ted C, 2017/07/21 00:15:25]

do we also need to call isTabInteractive() here?  if you're in the tab switcher,
would this show the pointer icons as if you were still showing the tab?

[jaebaek, 2017/07/21 10:03:04]

I made sure that the default pointer icon (pointer/arrow) will be used when the
isTabInteractive returns false. So the default one will be chose when other view
covers CompositorViewHolder as in the tab switcher. That makes me think calling
isTabInteractive() is not necessary here. It would be still okay to call it
though. Feel free to let me know if you believe it would be safer to do that. 

+        if (content == null) return null;
+        return content.getContainerView().onResolvePointerIcon(event, pointerIndex);
+    }
+
     /**
      * Creates a {@link CompositorView}.
      * @param c     The Context to create this {@link CompositorView} in.
      * @param attrs The AttributeSet used to create this {@link CompositorView}.
      */
     public CompositorViewHolder(Context c, AttributeSet attrs) {
         super(c, attrs);
 
         internalInit();
     }
@@ skipping 923 matching lines @@
             if (mPixelRect.width() == 0) {
                 mPixelRect.right = mPixelRect.left + 1;
             }
             if (mPixelRect.height() == 0) {
                 mPixelRect.bottom = mPixelRect.top + 1;
             }
             return mPixelRect;
         }
     }
 }