[Android] Perform eager gesture recognition on MotionEvents

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 00b3442010290dafd518dcdc525b0d1ad4100529..bb235bc871aaf0d7be9e799d3b64bed26fa5b05c 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -176,7 +176,9 @@ ContentViewCoreImpl::ContentViewCoreImpl(JNIEnv* env, jobject obj,
       view_android_(view_android),
       window_android_(window_android),
       device_orientation_(0),
-      geolocation_needs_pause_(false) {
+      geolocation_needs_pause_(false),
+      gesture_event_queue_(new GestureEventQueue(this)),
+      handling_touch_event_(false) {
   CHECK(web_contents) <<
       "A ContentViewCoreImpl should be created with a valid WebContents.";
 
@@ -304,6 +306,22 @@ void ContentViewCoreImpl::RenderViewReady() {
     SendOrientationChangeEventInternal();
 }
 
+void ContentViewCoreImpl::ForwardGestureEvent(
+    const blink::WebGestureEvent& event) {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> j_obj = java_ref_.get(env);
+  if (j_obj.is_null())
+    return;
+
+  if (Java_ContentViewCore_onForwardingGestureEvent(
+          env, j_obj.obj(), event.type, event.x, event.y))
+    return;
+
+  RenderWidgetHostViewAndroid* rwhv = GetRenderWidgetHostViewAndroid();
+  if (rwhv)
+    rwhv->SendGestureEvent(event);
+}
+
 RenderWidgetHostViewAndroid*
     ContentViewCoreImpl::GetRenderWidgetHostViewAndroid() {
   RenderWidgetHostView* rwhv = NULL;
@@ -497,20 +515,15 @@ void ContentViewCoreImpl::ShowSelectPopupMenu(
 }
 
 void ContentViewCoreImpl::ConfirmTouchEvent(InputEventAckState ack_result) {
-  JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jobject> j_obj = java_ref_.get(env);
-  if (j_obj.is_null())
-    return;
-  Java_ContentViewCore_confirmTouchEvent(env, j_obj.obj(),
-                                         static_cast<jint>(ack_result));
+  gesture_event_queue_->OnTouchEventAck(ack_result);
 }
 
-void ContentViewCoreImpl::UnhandledFlingStartEvent() {
+void ContentViewCoreImpl::UnhandledFlingStartEvent(float vx, float vy) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> j_obj = java_ref_.get(env);
   if (j_obj.is_null())
     return;
-  Java_ContentViewCore_unhandledFlingStartEvent(env, j_obj.obj());
+  Java_ContentViewCore_unhandledFlingStartEvent(env, j_obj.obj(), vx, vy);
 }
 
 void ContentViewCoreImpl::OnScrollUpdateGestureConsumed() {
@@ -521,16 +534,6 @@ void ContentViewCoreImpl::OnScrollUpdateGestureConsumed() {
   Java_ContentViewCore_onScrollUpdateGestureConsumed(env, j_obj.obj());
 }
 
-void ContentViewCoreImpl::HasTouchEventHandlers(bool need_touch_events) {
-  JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jobject> j_obj = java_ref_.get(env);
-  if (j_obj.is_null())
-    return;
-  Java_ContentViewCore_hasTouchEventHandlers(env,
-                                             j_obj.obj(),
-                                             need_touch_events);
-}
-
 bool ContentViewCoreImpl::HasFocus() {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
@@ -896,21 +899,30 @@ void ContentViewCoreImpl::SendOrientationChangeEvent(JNIEnv* env,
   }
 }
 
-jboolean ContentViewCoreImpl::SendTouchEvent(JNIEnv* env,
-                                             jobject obj,
-                                             jlong time_ms,
-                                             jint type,
-                                             jobjectArray pts) {
+void ContentViewCoreImpl::OnTouchEventHandlingBegin(JNIEnv* env,
+                                                    jobject obj,
+                                                    jlong time_ms,
+                                                    jint type,
+                                                    jobjectArray pts) {
+  DCHECK(!handling_touch_event_);
+  handling_touch_event_ = true;
+
+  blink::WebTouchEvent event;
+  TouchPoint::BuildWebTouchEvent(env, type, time_ms, GetDpiScale(), pts, event);
+  pending_touch_event_ = event;
+
+  pending_gesture_packet_ = GestureEventPacket::FromTouch(event);
+}
+
+void ContentViewCoreImpl::OnTouchEventHandlingEnd(JNIEnv* env, jobject obj) {
+  DCHECK(handling_touch_event_);
+  handling_touch_event_ = false;
+
+  gesture_event_queue_->OnGestureEventPacket(pending_gesture_packet_);
+
   RenderWidgetHostViewAndroid* rwhv = GetRenderWidgetHostViewAndroid();
-  if (rwhv) {
-    using blink::WebTouchEvent;
-    blink::WebTouchEvent event;
-    TouchPoint::BuildWebTouchEvent(env, type, time_ms, GetDpiScale(), pts,
-        event);
-    rwhv->SendTouchEvent(event);
-    return true;
-  }
-  return false;
+  if (rwhv)
+    rwhv->SendTouchEvent(pending_touch_event_);
 }
 
 float ContentViewCoreImpl::GetTouchPaddingDip() {
@@ -980,9 +992,12 @@ WebGestureEvent ContentViewCoreImpl::MakeGestureEvent(
 
 void ContentViewCoreImpl::SendGestureEvent(
     const blink::WebGestureEvent& event) {
-  RenderWidgetHostViewAndroid* rwhv = GetRenderWidgetHostViewAndroid();
-  if (rwhv)
-    rwhv->SendGestureEvent(event);
+  if (handling_touch_event_) {
+    pending_gesture_packet_.Push(event);
+    return;
+  }
+  gesture_event_queue_->OnGestureEventPacket(
+      GestureEventPacket::FromGesture(event));
 }
 
 void ContentViewCoreImpl::ScrollBegin(JNIEnv* env,