[Fullscreen Control] Prevent synthesizing mouse move events in test

The event dispatcher synthesizes mouse move events add feeds it to
FullscreenControlHost immediately after the browser enters fullscreen,
which interferes with the tests and makes the tests somewhat flaky.

This CL prevents WindowEventDispatcher from synthesizing mouse move
events. Note that this doesn't effect mouse move events coming from a
real device.

Bug: 841340
Change-Id: I850e4719e94c6a46dfbf14ae6a542b6ad76c6b7f
Reviewed-on: https://chromium-review.googlesource.com/1058557
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558905}

chrome/browser/ui/views/fullscreen_control/fullscreen_control_view_interactive_uitest.cc

@@ -27,6 +27,11 @@
 #include "ui/views/view.h"
 #include "url/gurl.h"
 
+#if defined(USE_AURA)
+#include "ui/aura/test/test_cursor_client.h"
+#include "ui/aura/window.h"
+#endif
+
 namespace {
 
 constexpr base::TimeDelta kPopupEventTimeout = base::TimeDelta::FromSeconds(5);
@@ -56,6 +61,25 @@ class FullscreenControlViewTest : public InProcessBrowserTest {
     InProcessBrowserTest::SetUp();
   }
 
+  void SetUpOnMainThread() override {
+#if defined(USE_AURA)
+    // This code prevents WindowEventDispatcher from synthesizing mouse move
+    // events when views get refreshed, so that they won't interfere with the
+    // tests. Note that new mouse move events directly coming from the real
+    // device will still pass through.
+    auto* root_window = browser()->window()->GetNativeWindow()->GetRootWindow();
+    cursor_client_ =
+        std::make_unique<aura::test::TestCursorClient>(root_window);
+    cursor_client_->DisableMouseEvents();
+#endif
+  }
+
+  void TearDownOnMainThread() override {
+#if defined(USE_AURA)
+    cursor_client_.reset();
+#endif
+  }
+
  protected:
   FullscreenControlHost* GetFullscreenControlHost() {
     BrowserView* browser_view =
@@ -122,6 +146,10 @@ class FullscreenControlViewTest : public InProcessBrowserTest {
  private:
   base::test::ScopedFeatureList scoped_feature_list_;
 
+#if defined(USE_AURA)
+  std::unique_ptr<aura::test::TestCursorClient> cursor_client_;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(FullscreenControlViewTest);
 };
 
@@ -392,10 +420,6 @@ IN_PROC_BROWSER_TEST_F(FullscreenControlViewTest,
 #endif
 IN_PROC_BROWSER_TEST_F(FullscreenControlViewTest,
                        MAYBE_KeyboardPopupInteraction) {
-  // TODO(yuweih): Test will fail if the cursor is at the top of the screen.
-  // That's because random mouse move events may pass from the browser to the
-  // host and interfere with the InputEntryMethod tracking. Consider fixing
-  // this.
   EnterActiveTabFullscreen();
   BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser());
   ASSERT_TRUE(browser_view->IsFullscreen());