Add helper class for tests using browser process hit testing

content/browser/site_per_process_browsertest.cc

Index: content/browser/site_per_process_browsertest.cc
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index c8fa716929efe53b4a79d82206f6b7027f69d236..754a60e119883a5c6494cf9cc7bf06f90442cb4b 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -20,6 +20,10 @@
 #include "base/test/test_timeouts.h"
 #include "base/thread_task_runner_handle.h"
 #include "build/build_config.h"
+#include "cc/surfaces/surface.h"
+#include "cc/surfaces/surface_manager.h"
+#include "content/browser/compositor/delegated_frame_host.h"
+#include "content/browser/compositor/surface_utils.h"
 #include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/navigator.h"
@@ -51,7 +55,12 @@
 #include "third_party/WebKit/public/web/WebSandboxFlags.h"
 #include "ui/gfx/switches.h"
 
+#if defined(USE_AURA)
+#include "content/browser/renderer_host/render_widget_host_view_aura.h"
+#endif
+
 #if defined(OS_MACOSX)
+#include "content/browser/renderer_host/render_widget_host_view_mac.h"
 #include "ui/base/test/scoped_preferred_scroller_style_legacy_mac.h"
 #endif
 
@@ -161,6 +170,76 @@ class RenderWidgetHostMouseEventMonitor {
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostMouseEventMonitor);
 };
 
+// Helper class to assist with hit testing surfaces in multiple processes.
+// WaitForSurfaceReady() will only return after a Surface from |target_view|
+// has been composited in the top-level frame's Surface. At that point,
+// browser process hit testing to target_view's Surface can succeed.
+class SurfaceHitTestReadyNotifier {

[nasko, 2016/02/26 18:33:51]

nit: Shouldn't this be in content_browser_test_utils_internal.*? It might be
useful beyond this file as we write more tests. Alternatively it can be moved
later if needed, though it will lower discoverability being here.

[kenrb, 2016/02/26 21:33:19]

Done.

+ public:
+  SurfaceHitTestReadyNotifier(RenderWidgetHostViewChildFrame* target_view)
+      : target_view_(target_view) {
+    surface_manager_ = GetSurfaceManager();
+  }
+  ~SurfaceHitTestReadyNotifier() {}
+
+  void WaitForSurfaceReady() {
+    root_surface_id_ = getRootSurfaceId();
+    if (containsSurfaceId())
+      return;
+
+    while (true) {
+      // TODO(kenrb): Need a better way to do this. If
+      // RenderWidgetHostViewBase lifetime observer lands (see
+      // https://codereview.chromium.org/1711103002/), we can add a callback
+      // from OnSwapCompositorFrame and avoid this busy waiting, which is very
+      // frequent in tests in this file.
+      base::RunLoop run_loop;
+      base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+          FROM_HERE, run_loop.QuitClosure(),
+          base::TimeDelta::FromMilliseconds(10));

[nasko, 2016/02/26 18:33:51]

TestTimeouts::tiny_timeout()?

[kenrb, 2016/02/26 21:33:19]

Done.

+      run_loop.Run();
+      if (containsSurfaceId())
+        break;
+    }
+  }
+
+ private:
+  bool containsSurfaceId() {

[nasko, 2016/02/26 18:33:51]

ContainsSurfaceId

[kenrb, 2016/02/26 21:33:18]

Done.

+    if (root_surface_id_.is_null())
+      return false;
+    for (cc::SurfaceId id : surface_manager_->GetSurfaceForId(root_surface_id_)
+                                ->referenced_surfaces()) {
+      if (id == target_view_->SurfaceIdForTesting())
+        return true;
+    }
+    return false;
+  }
+
+  cc::SurfaceId getRootSurfaceId() {

[nasko, 2016/02/26 18:33:51]

GetRootSurfaceId

[kenrb, 2016/02/26 21:33:19]

This method is removed as part of the refactor.

+#if defined(OS_MACOSX)
+    RenderWidgetHostViewMac* root_view = static_cast<RenderWidgetHostViewMac*>(
+        target_view_->FrameConnectorForTesting()
+            ->GetRootRenderWidgetHostViewForTesting());
+    return root_view->delegated_frame_host_->SurfaceIdForTesting();
+#elif defined(USE_AURA)
+    RenderWidgetHostViewAura* root_view =
+        static_cast<RenderWidgetHostViewAura*>(
+            target_view_->FrameConnectorForTesting()
+                ->GetRootRenderWidgetHostViewForTesting());
+    return root_view->GetDelegatedFrameHostForTesting()->SurfaceIdForTesting();
+#else
+    return cc::SurfaceId();
+#endif
+  }
+
+  cc::SurfaceManager* surface_manager_;
+  cc::SurfaceId root_surface_id_;
+  RenderWidgetHostViewChildFrame* target_view_;
+  base::Closure quit_;

[nasko, 2016/02/26 18:33:51]

Unused?

[kenrb, 2016/02/26 21:33:18]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(SurfaceHitTestReadyNotifier);
+};
+
 // Helper function that performs a surface hittest.
 void SurfaceHitTestTestHelper(
     Shell* shell,
@@ -196,20 +275,6 @@ void SurfaceHitTestTestHelper(
   RenderWidgetHostViewBase* rwhv_child = static_cast<RenderWidgetHostViewBase*>(
       child_node->current_frame_host()->GetRenderWidgetHost()->GetView());
 
-  // We need to wait for a compositor frame from the child frame, at which
-  // point its surface will be created.
-  while (rwhv_child->RendererFrameNumber() <= 0) {
-    // TODO(lazyboy): Find a better way to avoid sleeping like this. See
-    // http://crbug.com/405282 for details.
-    base::RunLoop run_loop;
-    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
-        FROM_HERE, run_loop.QuitClosure(),
-        base::TimeDelta::FromMilliseconds(10));
-    run_loop.Run();
-  }
-
-  uint32_t cur_render_frame_number = root_view->RendererFrameNumber();
-
   // Target input event to child frame.
   blink::WebMouseEvent child_event;
   child_event.type = blink::WebInputEvent::MouseDown;
@@ -221,31 +286,9 @@ void SurfaceHitTestTestHelper(
   child_frame_monitor.ResetEventReceived();
   router->RouteMouseEvent(root_view, &child_event);
 
-  while (!child_frame_monitor.EventWasReceived()) {
-    // This is working around a big synchronization problem. It is very
-    // difficult to know if we have received a compositor frame from the
-    // main frame renderer *after* it received the child frame's surface
-    // ID. Hit testing won't work until this happens. So if the hit test
-    // fails then we wait for another frame to arrive and try again.
-    // TODO(kenrb): We need a better way to do all of this, possibly coming
-    // from http://crbug.com/405282.
-    while (root_view->RendererFrameNumber() <= cur_render_frame_number) {
-      base::RunLoop run_loop;
-      base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
-          FROM_HERE, run_loop.QuitClosure(),
-          base::TimeDelta::FromMilliseconds(10));
-      run_loop.Run();
-    }
-    cur_render_frame_number = root_view->RendererFrameNumber();
-    child_event.type = blink::WebInputEvent::MouseDown;
-    child_event.button = blink::WebPointerProperties::ButtonLeft;
-    child_event.x = 75;
-    child_event.y = 75;
-    child_event.clickCount = 1;
-    main_frame_monitor.ResetEventReceived();
-    child_frame_monitor.ResetEventReceived();
-    router->RouteMouseEvent(root_view, &child_event);
-  }
+  SurfaceHitTestReadyNotifier notifier(
+      static_cast<RenderWidgetHostViewChildFrame*>(rwhv_child));
+  notifier.WaitForSurfaceReady();
 
   EXPECT_TRUE(child_frame_monitor.EventWasReceived());
   EXPECT_EQ(23, child_frame_monitor.event().x);
@@ -823,17 +866,9 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
   RenderWidgetHostViewBase* rwhv_child = static_cast<RenderWidgetHostViewBase*>(
       child_node->current_frame_host()->GetRenderWidgetHost()->GetView());
 
-  // We need to wait for a compositor frame from the child frame, at which
-  // point its surface will be created.
-  while (rwhv_child->RendererFrameNumber() <= 0) {
-    // TODO(lazyboy): Find a better way to avoid sleeping like this. See
-    // http://crbug.com/405282 for details.
-    base::RunLoop run_loop;
-    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
-        FROM_HERE, run_loop.QuitClosure(),
-        base::TimeDelta::FromMilliseconds(10));
-    run_loop.Run();
-  }
+  SurfaceHitTestReadyNotifier notifier(
+      static_cast<RenderWidgetHostViewChildFrame*>(rwhv_child));
+  notifier.WaitForSurfaceReady();
 
   // Target input event to child frame.
   blink::WebMouseEvent child_event;