Add UMA stats for pen palette

ash/common/system/chromeos/palette/common_palette_tool.cc

Index: ash/common/system/chromeos/palette/common_palette_tool.cc
diff --git a/ash/common/system/chromeos/palette/common_palette_tool.cc b/ash/common/system/chromeos/palette/common_palette_tool.cc
index 9f8faf4c71dc6f65c38b75c9cdbe360a63780529..86e443c549e8f14a3f3116798e4f3ee4d6df8cf9 100644
--- a/ash/common/system/chromeos/palette/common_palette_tool.cc
+++ b/ash/common/system/chromeos/palette/common_palette_tool.cc
@@ -10,6 +10,7 @@
 #include "ash/common/system/tray/hover_highlight_view.h"
 #include "ash/common/system/tray/view_click_listener.h"
 #include "base/logging.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "grit/ash_resources.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -52,6 +53,7 @@ void CommonPaletteTool::OnViewDestroyed() {
 
 void CommonPaletteTool::OnEnable() {
   PaletteTool::OnEnable();
+  start_time_ = base::TimeTicks::Now();
 
   if (highlight_view_) {
     highlight_view_->SetHighlight(true);
@@ -62,6 +64,18 @@ void CommonPaletteTool::OnEnable() {
 void CommonPaletteTool::OnDisable() {
   PaletteTool::OnDisable();
 
+  if (GetToolId() == PaletteToolId::LASER_POINTER) {
+    UMA_HISTOGRAM_CUSTOM_TIMES("Ash.Shelf.Palette.InLaserPointerMode",
+                               base::TimeTicks::Now() - start_time_,
+                               base::TimeDelta::FromMilliseconds(100),
+                               base::TimeDelta::FromHours(1), 50);
+  } else if (GetToolId() == PaletteToolId::MAGNIFY) {
+    UMA_HISTOGRAM_CUSTOM_TIMES("Ash.Shelf.Palette.InMagnifyMode",
+                               base::TimeTicks::Now() - start_time_,
+                               base::TimeDelta::FromMilliseconds(100),
+                               base::TimeDelta::FromHours(1), 50);
+  }

[stevenjb, 2016/09/13 16:32:18]

Do we anticipate adding more tools? If so I would move this into a helper
function, e.g. AddHistogramTimes().

[xiaoyinh(OOO Sep 11-29), 2016/09/14 00:51:24]

Done.

+
   if (highlight_view_) {
     highlight_view_->SetHighlight(false);
     highlight_view_->SetRightIconVisible(false);
@@ -69,10 +83,20 @@ void CommonPaletteTool::OnDisable() {
 }
 
 void CommonPaletteTool::OnViewClicked(views::View* sender) {
-  if (enabled())
+  delegate()->RecordPaletteOptionsUsage(
+      PaletteToolIdToPaletteTrayOptions(GetToolId()));
+  if (enabled()) {
     delegate()->DisableTool(GetToolId());
-  else
+    if (GetToolId() == PaletteToolId::LASER_POINTER) {
+      delegate()->RecordPaletteModeCancellation(
+          PaletteModeCancelType::PALETTE_MODE_LASER_POINTER_CANCELLED);
+    } else if (GetToolId() == PaletteToolId::MAGNIFY) {
+      delegate()->RecordPaletteModeCancellation(
+          PaletteModeCancelType::PALETTE_MODE_MAGNIFY_CANCELLED);
+    }

[stevenjb, 2016/09/13 16:32:18]

same here.

[xiaoyinh(OOO Sep 11-29), 2016/09/14 00:51:24]

Done.

+  } else {
     delegate()->EnableTool(GetToolId());
+  }
 }
 
 views::View* CommonPaletteTool::CreateDefaultView(const base::string16& name) {