Remove unnecessary spin in ToolTipController

ui/views/corewm/tooltip_controller.cc

Index: ui/views/corewm/tooltip_controller.cc
diff --git a/ui/views/corewm/tooltip_controller.cc b/ui/views/corewm/tooltip_controller.cc
index cd1792ffa29d03692804fa4162d8a450adcb171c..66392098b1ba9cc4a86f4b05e4b0afc8b9059df5 100644
--- a/ui/views/corewm/tooltip_controller.cc
+++ b/ui/views/corewm/tooltip_controller.cc
@@ -25,12 +25,12 @@
 #include "ui/gfx/text_elider.h"
 #include "ui/views/corewm/tooltip.h"
 #include "ui/views/widget/tooltip_manager.h"
+#include "ui/wm/public/tooltip_client.h"
 
 namespace views {
 namespace corewm {
 namespace {
 
-const int kTooltipTimeoutMs = 500;
 const int kDefaultTooltipShownTimeoutMs = 10000;
 #if defined(OS_WIN)
 // Drawing a long word in tooltip is very slow on Windows. crbug.com/513693
@@ -129,11 +129,7 @@ TooltipController::TooltipController(std::unique_ptr<Tooltip> tooltip)
       tooltip_id_(NULL),
       tooltip_window_at_mouse_press_(NULL),
       tooltip_(std::move(tooltip)),
-      tooltips_enabled_(true) {
-  tooltip_timer_.Start(FROM_HERE,
-      base::TimeDelta::FromMilliseconds(kTooltipTimeoutMs),
-      this, &TooltipController::TooltipTimerFired);
-}
+      tooltips_enabled_(true) {}
 
 TooltipController::~TooltipController() {
   if (tooltip_window_)
@@ -150,9 +146,7 @@ void TooltipController::UpdateTooltip(aura::Window* target) {
     UpdateIfRequired();
 
   // Reset |tooltip_window_at_mouse_press_| if the moving within the same window
-  // but over a region that has different tooltip text. By resetting
-  // |tooltip_window_at_mouse_press_| we ensure the next time the timer fires
-  // we'll requery for the tooltip text.
+  // but over a region that has different tooltip text.
   // This handles the case of clicking on a view, moving within the same window
   // but over a different view, than back to the original.
   if (tooltip_window_at_mouse_press_ &&
@@ -160,17 +154,6 @@ void TooltipController::UpdateTooltip(aura::Window* target) {
       aura::client::GetTooltipText(target) != tooltip_text_at_mouse_press_) {
     tooltip_window_at_mouse_press_ = NULL;
   }
-
-  // If we had stopped the tooltip timer for some reason, we must restart it if
-  // there is a change in the tooltip.
-  if (!tooltip_timer_.IsRunning()) {
-    if (tooltip_window_ != target || (tooltip_window_ &&
-        tooltip_text_ != aura::client::GetTooltipText(tooltip_window_))) {
-      tooltip_timer_.Start(FROM_HERE,
-          base::TimeDelta::FromMilliseconds(kTooltipTimeoutMs),
-          this, &TooltipController::TooltipTimerFired);
-    }
-  }
 }
 
 void TooltipController::SetTooltipShownTimeout(aura::Window* target,
@@ -211,10 +194,10 @@ void TooltipController::OnMouseEvent(ui::MouseEvent* event) {
         target = GetTooltipTarget(*event, &curr_mouse_loc_);
       }
       SetTooltipWindow(target);
-      if (tooltip_timer_.IsRunning())
-        tooltip_timer_.Reset();
 
-      if (tooltip_->IsVisible())
+      if (tooltip_->IsVisible() ||
+          (tooltip_window_ &&

[sky, 2017/01/12 20:15:18]

How come you are adding this condition? 

[chengx, 2017/01/13 01:17:51]

Because before this change, OnMouseEvent() only triggers UpdateIfRequired() when
tooltip_->IsVisible() is true. It was okay because there was a repeating check.
However, after removing the repeating check, we need to rely on OnMouseEvent()
further when tooltip is invisible. TooltipControllerTest2.* in
ui/views/corewm/tooltip_controller_unittest.cc reflect this logic. 

+           tooltip_text_ != aura::client::GetTooltipText(tooltip_window_)))
         UpdateIfRequired();
       break;
     }
@@ -232,10 +215,6 @@ void TooltipController::OnMouseEvent(ui::MouseEvent* event) {
       // Hide the tooltip for click, release, drag, wheel events.
       if (tooltip_->IsVisible())
         tooltip_->Hide();
-
-      // Don't reshow the tooltip during scroll.
-      if (tooltip_timer_.IsRunning())
-        tooltip_timer_.Reset();
       break;
     default:
       break;
@@ -255,6 +234,10 @@ void TooltipController::OnCancelMode(ui::CancelModeEvent* event) {
   SetTooltipWindow(NULL);
 }
 
+void TooltipController::OnCursorVisibilityChanged(bool is_visible) {
+  UpdateIfRequired();
+}
+
 void TooltipController::OnWindowDestroyed(aura::Window* window) {
   if (tooltip_window_ == window) {
     tooltip_->Hide();
@@ -263,20 +246,23 @@ void TooltipController::OnWindowDestroyed(aura::Window* window) {
   }
 }
 
+void TooltipController::OnWindowPropertyChanged(aura::Window* window,
+                                                const void* key,
+                                                intptr_t old) {
+  if ((key == aura::client::kTooltipIdKey ||
+       key == aura::client::kTooltipTextKey) &&
+      window && tooltip_window_ == window &&

[sky, 2017/01/12 20:15:18]

Why do you need to check window and tooltip_window_ == window here? The observer
is only added for tooltip_window_. I could see a DCHECK if you want.

[chengx, 2017/01/13 01:17:51]

You are right. I have removed those two checks.

+      aura::client::GetTooltipText(window) != base::string16() &&
+      (tooltip_text_ != aura::client::GetTooltipText(window) ||
+       tooltip_id_ != aura::client::GetTooltipId(window)))
+    UpdateIfRequired();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // TooltipController private:
 
-void TooltipController::TooltipTimerFired() {
-  UpdateIfRequired();
-}
-
 void TooltipController::TooltipShownTimerFired() {
   tooltip_->Hide();
-
-  // Since the user presumably no longer needs the tooltip, we also stop the
-  // tooltip timer so that tooltip does not pop back up. We will restart this
-  // timer if the tooltip changes (see UpdateTooltip()).
-  tooltip_timer_.Stop();
 }
 
 void TooltipController::UpdateIfRequired() {
@@ -309,9 +295,6 @@ void TooltipController::UpdateIfRequired() {
   ids_differ = tooltip_id_ != tooltip_id;
   tooltip_id_ = tooltip_id;
 
-  // We add the !tooltip_->IsVisible() below because when we come here from
-  // TooltipTimerFired(), the tooltip_text may not have changed but we still
-  // want to update the tooltip because the timer has fired.
   // If we come here from UpdateTooltip(), we have already checked for tooltip
   // visibility and this check below will have no effect.
   if (tooltip_text_ != tooltip_text || !tooltip_->IsVisible() || ids_differ) {