Diagnostic for issue 882458.

This is a CL with temporary diagnostic code for
https://crbug.com/882458.

This CL will be landed and left in ToT long enough to collect data, and
then reverted quickly, and certainly prior to the next stable branch
cut.

Bug: 882458
Change-Id: I5c5d1f2e26a032f743a86af6f335e6942f97e423
Reviewed-on: https://chromium-review.googlesource.com/1227130Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591468}

content/browser/renderer_host/cursor_manager.cc

@@ -6,18 +6,39 @@
 
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 
+#if defined(OS_WIN)
+#include "base/command_line.h"
+#include "content/public/common/content_switches.h"
+#endif
+
 namespace content {
 
 CursorManager::CursorManager(RenderWidgetHostViewBase* root)
     : view_under_cursor_(root),
       root_view_(root),
-      tooltip_observer_for_testing_(nullptr) {}
+#if defined(OS_WIN)
+      enable_logging_for_test_(false),
+#endif
+      tooltip_observer_for_testing_(nullptr) {
+#if defined(OS_WIN)
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kBrowserTest))
+    enable_logging_for_test_ = true;
+#endif
+}
 
 CursorManager::~CursorManager() {}
 
 void CursorManager::UpdateCursor(RenderWidgetHostViewBase* view,
                                  const WebCursor& cursor) {
   cursor_map_[view] = cursor;
+#if defined(OS_WIN)
+  if (enable_logging_for_test_) {
+    enable_logging_for_test_ = false;
+    LOG(ERROR) << "Setting first cursor for view = " << view
+               << ", this = " << this;
+  }
+#endif
   if (view == view_under_cursor_)
     root_view_->DisplayCursor(cursor);
 }

content/browser/renderer_host/cursor_manager.h

@@ -7,6 +7,7 @@
 
 #include <map>
 
+#include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "content/common/cursors/webcursor.h"
 
@@ -69,6 +70,11 @@ class CONTENT_EXPORT CursorManager {
   // cursor needs to change.
   RenderWidgetHostViewBase* root_view_;
 
+#if defined(OS_WIN)
+  // Added to help diagnose http://crbug.com/882458. This will be removed before
+  // the branch promotes to stable.
+  bool enable_logging_for_test_;
+#endif
   TooltipObserver* tooltip_observer_for_testing_;
 };
 

content/browser/site_per_process_hit_test_browsertest.cc

@@ -2920,6 +2920,31 @@ class CursorMessageFilter : public content::BrowserMessageFilter {
 
 namespace {
 
+#if defined(OS_WIN)
+// Temporary diagnostic code for https://crbug.com/882458.
+class CursorUpdateEventLogger
+    : public content::RenderWidgetHost::InputEventObserver {
+ public:
+  CursorUpdateEventLogger() = default;
+  ~CursorUpdateEventLogger() override {}
+
+  void OnInputEvent(const blink::WebInputEvent& event) override {
+    blink::WebInputEvent::Type type = event.GetType();
+    if (blink::WebInputEvent::IsMouseEventType(type)) {
+      auto mouse_event = static_cast<const blink::WebMouseEvent&>(event);
+      auto pos = mouse_event.PositionInWidget();
+      LOG(INFO) << "EventType = " << blink::WebInputEvent::GetName(type)
+                << ", pos = (" << pos.x << "," << pos.y;
+    } else {
+      LOG(INFO) << "EventType = " << blink::WebInputEvent::GetName(type);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CursorUpdateEventLogger);
+};
+#endif
+
 // Verify that we receive a mouse cursor update message when we mouse over
 // a text field contained in an out-of-process iframe.
 void CursorUpdateReceivedFromCrossSiteIframeHelper(
@@ -2931,6 +2956,15 @@ void CursorUpdateReceivedFromCrossSiteIframeHelper(
 
   auto* web_contents = static_cast<WebContentsImpl*>(shell->web_contents());
   FrameTreeNode* root = web_contents->GetFrameTree()->root();
+#if defined(OS_WIN)
+  // Install observer to try and see if what event might be triggering an
+  // unexpected cursor being set. *Hopefully* this observer gets installed
+  // before any events go through the main frame RenderWidgetHost.
+  // https://crbug.com/882458
+  CursorUpdateEventLogger main_frame_event_logger;
+  root->current_frame_host()->GetRenderWidgetHost()->AddInputEventObserver(
+      &main_frame_event_logger);
+#endif
 
   FrameTreeNode* child_node = root->child_at(0);
   EXPECT_NE(shell->web_contents()->GetSiteInstance(),
@@ -3007,6 +3041,10 @@ void CursorUpdateReceivedFromCrossSiteIframeHelper(
   CursorInfo cursor_info;
   cursor.GetCursorInfo(&cursor_info);
   EXPECT_EQ(cursor_info.type, blink::WebCursorInfo::kTypeIBeam);
+#if defined(OS_WIN)
+  root->current_frame_host()->GetRenderWidgetHost()->RemoveInputEventObserver(
+      &main_frame_event_logger);
+#endif
 }
 
 }  // namespace