[Android] Provide unhandled tap event notifications

Allow notifications of unhandled taps via the GestureStateListener.  This change
makes GestureTap events blocking, but there are several use-cases for which this
will be necessary, e.g., WebView and contextual search.

NOTRY=true

Review URL: https://codereview.chromium.org/218633008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@261431 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/android/content_view_core_impl.cc

@@ -615,6 +615,12 @@ void ContentViewCoreImpl::OnGestureEventAck(const blink::WebGestureEvent& event,
     case WebInputEvent::GesturePinchEnd:
       Java_ContentViewCore_onPinchEndEventAck(env, j_obj.obj());
       break;
+    case WebInputEvent::GestureTap:
+      if (ack_result != INPUT_EVENT_ACK_STATE_CONSUMED) {
+        Java_ContentViewCore_onTapEventNotConsumed(
+            env, j_obj.obj(), event.x * dpi_scale(), event.y * dpi_scale());
+      }
+      break;
     case WebInputEvent::GestureDoubleTap:
       Java_ContentViewCore_onDoubleTapEventAck(env, j_obj.obj());
       break;

content/browser/renderer_host/input/input_router_impl_unittest.cc

@@ -1285,12 +1285,17 @@ TEST_F(InputRouterImplTest, DoubleTapGestureDependsOnFirstTap) {
   EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
 
   // The GestureTapUnconfirmed is converted into a tap, as the touch action is
-  // auto.
+  // none.
   SimulateGestureEvent(WebInputEvent::GestureTapUnconfirmed,
                        WebGestureEvent::Touchscreen);
+  EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
+  // This test will become invalid if GestureTap stops requiring an ack.
+  ASSERT_TRUE(!WebInputEventTraits::IgnoresAckDisposition(
+      WebInputEvent::GestureTap));
+  EXPECT_EQ(2, client_->in_flight_event_count());
   SendInputEventACK(WebInputEvent::GestureTap,
                     INPUT_EVENT_ACK_STATE_CONSUMED);
-  EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
+  EXPECT_EQ(1, client_->in_flight_event_count());
 
   // This tap gesture is dropped, since the GestureTapUnconfirmed was turned
   // into a tap.
@@ -1312,8 +1317,10 @@ TEST_F(InputRouterImplTest, DoubleTapGestureDependsOnFirstTap) {
   SimulateGestureEvent(WebInputEvent::GestureDoubleTap,
                        WebGestureEvent::Touchscreen);
   // This test will become invalid if GestureDoubleTap stops requiring an ack.
-  DCHECK(!WebInputEventTraits::IgnoresAckDisposition(
+  ASSERT_TRUE(!WebInputEventTraits::IgnoresAckDisposition(
       WebInputEvent::GestureDoubleTap));
+  EXPECT_EQ(1, client_->in_flight_event_count());
+  SendInputEventACK(WebInputEvent::GestureTap, INPUT_EVENT_ACK_STATE_CONSUMED);
   EXPECT_EQ(0, client_->in_flight_event_count());
 }
 

content/common/input/web_input_event_traits.cc

@@ -322,7 +322,6 @@ bool WebInputEventTraits::IgnoresAckDisposition(
     case WebInputEvent::GestureTapDown:
     case WebInputEvent::GestureShowPress:
     case WebInputEvent::GestureTapCancel:
-    case WebInputEvent::GestureTap:
     case WebInputEvent::GesturePinchBegin:
     case WebInputEvent::GesturePinchEnd:
     case WebInputEvent::GestureScrollBegin:

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

@@ -1286,6 +1286,15 @@ public class ContentViewCore
         updateGestureStateListener(GestureEventType.PINCH_END);
     }
 
+    @SuppressWarnings("unused")
+    @CalledByNative
+    private void onTapEventNotConsumed(int x, int y) {
+        for (mGestureStateListenersIterator.rewind();
+                mGestureStateListenersIterator.hasNext();) {
+            mGestureStateListenersIterator.next().onUnhandledTapEvent(x, y);
+        }
+    }
+
     @SuppressWarnings("unused")
     @CalledByNative
     private void onDoubleTapEventAck() {

content/public/android/java/src/org/chromium/content_public/browser/GestureStateListener.java

@@ -61,4 +61,9 @@ public class GestureStateListener {
      * Called when the scroll offsets or extents may have changed.
      */
     public void onScrollOffsetOrExtentChanged(int scrollOffsetY, int scrollExtentY) {}
+
+    /*
+     * Called when a tap event was not handled by the renderer.
+     */
+    public void onUnhandledTapEvent(int x, int y) {}
 }