Consume mouse button events on toolbar

A regression was letting mouse button click events on toolbar
to be passed down to content layer, and causing the content
hidden behind the toolbar react to the events as well, while
they should have triggered corresponding action on the toolbar
only. This CL stop the leak.

BUG=740855

Change-Id: I3e0e3ede01ba73d589b3d3e3fa3a55b2577c0957
Reviewed-on: https://chromium-review.googlesource.com/582053
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#489123}

chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarLayout.java

@@ -15,6 +15,8 @@
 import android.graphics.drawable.Drawable;
 import android.os.SystemClock;
 import android.util.AttributeSet;
+import android.view.InputDevice;
+import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
@@ -534,6 +536,21 @@ protected void updateTabCountVisuals(int numberOfTabs) { }
      */
     protected void onDefaultSearchEngineChanged() { }
 
+    @Override
+    public boolean onGenericMotionEvent(MotionEvent event) {
+        // Consumes mouse button events on toolbar so they don't get leaked to content layer.
+        // See https://crbug.com/740855.
+        if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0
+                && event.getToolType(0) == MotionEvent.TOOL_TYPE_MOUSE) {
+            int action = event.getActionMasked();
+            if (action == MotionEvent.ACTION_BUTTON_PRESS
+                    || action == MotionEvent.ACTION_BUTTON_RELEASE) {
+                return true;
+            }
+        }
+        return super.onGenericMotionEvent(event);
+    }
+
     @Override
     public void getLocationBarContentRect(Rect outRect) {
         View container = getLocationBar().getContainerView();