Update upgrade app menu icons for MD/vectorization.

BUG=559407
TEST=chrome --simulate-critical-update --top-chrome-md=material

Review URL: https://codereview.chromium.org/1676623002

Cr-Commit-Position: refs/heads/master@{#374179}
diff --git a/chrome/browser/upgrade_detector.cc b/chrome/browser/upgrade_detector.cc
index ab3a4cf..23db83d 100644
--- a/chrome/browser/upgrade_detector.cc
+++ b/chrome/browser/upgrade_detector.cc
@@ -14,6 +14,9 @@
 #include "components/prefs/pref_registry_simple.h"
 #include "content/public/browser/notification_service.h"
 #include "grit/theme_resources.h"
+#include "ui/gfx/color_palette.h"
+#include "ui/gfx/paint_vector_icon.h"
+#include "ui/gfx/vector_icons_public.h"
 
 // How long to wait between checks for whether the user has been idle.
 static const int kIdleRepeatingTimerWait = 10;  // Minutes (seconds if testing).
@@ -36,23 +39,27 @@
   registry->RegisterBooleanPref(prefs::kAttemptedToEnableAutoupdate, false);
 }
 
-int UpgradeDetector::GetIconResourceID() {
+gfx::Image UpgradeDetector::GetIcon() {
+  SkColor color = gfx::kPlaceholderColor;
   switch (upgrade_notification_stage_) {
     case UPGRADE_ANNOYANCE_NONE:
-      return 0;
+      return gfx::Image();
     case UPGRADE_ANNOYANCE_LOW:
-      return IDR_UPDATE_MENU_SEVERITY_LOW;
+      color = gfx::kGoogleGreen700;
+      break;
     case UPGRADE_ANNOYANCE_ELEVATED:
-      return IDR_UPDATE_MENU_SEVERITY_MEDIUM;
+      color = gfx::kGoogleYellow700;
+      break;
     case UPGRADE_ANNOYANCE_HIGH:
-      return IDR_UPDATE_MENU_SEVERITY_HIGH;
     case UPGRADE_ANNOYANCE_SEVERE:
-      return IDR_UPDATE_MENU_SEVERITY_HIGH;
     case UPGRADE_ANNOYANCE_CRITICAL:
-      return IDR_UPDATE_MENU_SEVERITY_HIGH;
+      color = gfx::kGoogleRed700;
+      break;
   }
-  NOTREACHED();
-  return 0;
+  DCHECK_NE(gfx::kPlaceholderColor, color);
+
+  return gfx::Image(
+      gfx::CreateVectorIcon(gfx::VectorIconId::UPGRADE_MENU_ITEM, 16, color));
 }
 
 UpgradeDetector::UpgradeDetector()