Block internal PlatformEvents before they are dispatched in touchview.

ui/events/platform/platform_event_source_unittest.cc

Index: ui/events/platform/platform_event_source_unittest.cc
diff --git a/ui/events/platform/platform_event_source_unittest.cc b/ui/events/platform/platform_event_source_unittest.cc
index cdbd0c4b35cb07be1c96df7cb3420fac574c966f..2f91b9ed0efc4f5684d3461e822cf6fd3c921685 100644
--- a/ui/events/platform/platform_event_source_unittest.cc
+++ b/ui/events/platform/platform_event_source_unittest.cc
@@ -11,6 +11,7 @@
 #include "base/run_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/platform/platform_event_dispatcher.h"
+#include "ui/events/platform/platform_event_filter.h"
 #include "ui/events/platform/platform_event_observer.h"
 #include "ui/events/platform/scoped_event_dispatcher.h"
 
@@ -136,6 +137,24 @@ class TestPlatformEventObserver : public PlatformEventObserver {
   DISALLOW_COPY_AND_ASSIGN(TestPlatformEventObserver);
 };
 
+class TestPlatformEventFilter : public PlatformEventFilter {
+ public:
+  TestPlatformEventFilter() {
+    PlatformEventSource::GetInstance()->AddPlatformEventFilter(this);
+  }
+
+  virtual ~TestPlatformEventFilter() {
+    PlatformEventSource::GetInstance()->RemovePlatformEventFilter(this);
+  }
+
+  virtual bool ShouldDispatchEvent(const PlatformEvent& event) OVERRIDE {
+    return false;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestPlatformEventFilter);
+};
+
 class PlatformEventTest : public testing::Test {
  public:
   PlatformEventTest() {}
@@ -234,6 +253,29 @@ TEST_F(PlatformEventTest, ObserverBasic) {
   EXPECT_EQ(0u, list_observer.size());
 }
 
+// Tests that filtered events are not observed or dispatched.
+TEST_F(PlatformEventTest, FilterBasic) {
+  std::vector<int> list;
+  scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
+  TestPlatformEventDispatcher dispatcher(1, &list);
+  TestPlatformEventObserver observer(2, &list);
+  source()->Dispatch(*event);
+  EXPECT_EQ(2u, list.size());
+  list.clear();
+  {
+    TestPlatformEventFilter filter;
+    scoped_ptr<PlatformEvent> event(CreatePlatformEvent());
+    source()->Dispatch(*event);
+    ASSERT_EQ(0u, list.size());
+    list.clear();
+  }
+
+  list.clear();
+  event = CreatePlatformEvent();
+  source()->Dispatch(*event);
+  EXPECT_EQ(2u, list.size());
+}
+
 // Tests that observers receive events in the correct order.
 TEST_F(PlatformEventTest, ObserverOrder) {
   std::vector<int> list_observer;