Resend unconsumed scroll update from guest back to embedder (WebView Scroll Bubble).

content/browser/renderer_host/render_widget_host_view_aura_unittest.cc

Index: content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
index dae4136a014f828eac0b9d269f26f1775f25242a..5bfcd4044edee4eff1493c920f4f0dd4ed53b483 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
@@ -2601,8 +2601,10 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest,
   EXPECT_EQ(OVERSCROLL_NONE, overscroll_mode());
 
   // Indicate the end of the scrolling from the touchpad.
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
   SimulateGestureFlingStartEvent(-1200.f, 0.f, blink::WebGestureDeviceTouchpad);
-  EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
+  EXPECT_EQ(2U, GetSentMessageCountAndResetSink());
 
   // Start another scroll. This time, do not consume any scroll events.
   SimulateWheelEvent(0, -5, 0, true);    // sent directly
@@ -2721,9 +2723,11 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest,
   // Send a fling start, but with a small velocity, so that the overscroll is
   // aborted. The fling should proceed to the renderer, through the gesture
   // event filter.
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
   SimulateGestureFlingStartEvent(0.f, 0.1f, blink::WebGestureDeviceTouchpad);
   EXPECT_EQ(OVERSCROLL_NONE, overscroll_mode());
-  EXPECT_EQ(1U, sink_->message_count());
+  EXPECT_EQ(2U, sink_->message_count());
 }
 
 // Same as ScrollEventsOverscrollWithFling, but with zero velocity. Checks that
@@ -2763,9 +2767,11 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest,
   // Send a fling start, but with a small velocity, so that the overscroll is
   // aborted. The fling should proceed to the renderer, through the gesture
   // event filter.
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
   SimulateGestureFlingStartEvent(10.f, 0.f, blink::WebGestureDeviceTouchpad);
   EXPECT_EQ(OVERSCROLL_NONE, overscroll_mode());
-  EXPECT_EQ(1U, sink_->message_count());
+  EXPECT_EQ(2U, sink_->message_count());
 }
 
 // Tests that a fling in the opposite direction of the overscroll cancels the
@@ -3348,9 +3354,11 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest,
 
   // Touchpad scroll can end with a zero-velocity fling. But it is not
   // dispatched, but it should still reset the overscroll controller state.
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
   SimulateGestureFlingStartEvent(0.f, 0.f, blink::WebGestureDeviceTouchpad);
   EXPECT_TRUE(ScrollStateIsUnknown());
-  EXPECT_EQ(0U, sink_->message_count());
+  EXPECT_EQ(1U, sink_->message_count());
 
   // Dropped flings should neither propagate *nor* indicate that they were
   // consumed and have triggered a fling animation (as tracked by the router).
@@ -3360,7 +3368,7 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest,
   SimulateWheelEvent(-60, 0, 0, true);   // enqueued
   SimulateWheelEvent(-100, 0, 0, true);  // coalesced into previous event
   EXPECT_TRUE(ScrollStateIsUnknown());
-  EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
+  EXPECT_EQ(2U, GetSentMessageCountAndResetSink());
 
   // The first wheel scroll did not scroll content. Overscroll should not start
   // yet, since enough hasn't been scrolled.
@@ -3375,11 +3383,14 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest,
   EXPECT_TRUE(ScrollStateIsOverscrolling());
   EXPECT_EQ(0U, sink_->message_count());
 
+  // The GestureScrollBegin will reset the delegate's mode, so check it here.
+  EXPECT_EQ(OVERSCROLL_WEST, overscroll_delegate()->current_mode());
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
   SimulateGestureFlingStartEvent(0.f, 0.f, blink::WebGestureDeviceTouchpad);
   EXPECT_EQ(OVERSCROLL_NONE, overscroll_mode());
-  EXPECT_EQ(OVERSCROLL_WEST, overscroll_delegate()->completed_mode());
   EXPECT_TRUE(ScrollStateIsUnknown());
-  EXPECT_EQ(0U, sink_->message_count());
+  EXPECT_EQ(1U, sink_->message_count());
   EXPECT_FALSE(parent_host_->input_router()->HasPendingEvents());
 }
 
@@ -3599,6 +3610,8 @@ TEST_F(RenderWidgetHostViewAuraOverscrollTest, ScrollDeltasResetOnEnd) {
   EXPECT_EQ(OVERSCROLL_NONE, overscroll_mode());
   EXPECT_EQ(15.f, overscroll_delta_x());
   EXPECT_EQ(-5.f, overscroll_delta_y());
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
   SimulateGestureFlingStartEvent(0.f, 0.1f, blink::WebGestureDeviceTouchpad);
   EXPECT_EQ(0.f, overscroll_delta_x());
   EXPECT_EQ(0.f, overscroll_delta_y());