Add heuristics to limit showing of new backspace UI bubble.

chrome/browser/ui/browser_command_controller.cc

Index: chrome/browser/ui/browser_command_controller.cc
diff --git a/chrome/browser/ui/browser_command_controller.cc b/chrome/browser/ui/browser_command_controller.cc
index 5d97b8ff461ae14572d5f7b648dc4b21dd149d89..d411bed3f4cd09cd76087b5bd160178993427501 100644
--- a/chrome/browser/ui/browser_command_controller.cc
+++ b/chrome/browser/ui/browser_command_controller.cc
@@ -321,21 +321,23 @@ void BrowserCommandController::ExecuteCommandWithDisposition(
   switch (id) {
     // Navigation commands
     case IDC_BACKSPACE_BACK:
-      if (!base::FeatureList::IsEnabled(kBackspaceGoesBackFeature)) {
-        browser_->window()->ShowNewBackShortcutBubble(false);
-        break;
-      }
-      // FALL THROUGH

[Peter Kasting, 2016/06/07 08:04:23]

I know you're super disappointed to see these fallthroughs disappear.

[Matt Giuca, 2016/06/08 01:29:03]

:'(

+      if (base::FeatureList::IsEnabled(kBackspaceGoesBackFeature))
+        GoBack(browser_, disposition);
+      else
+        browser_->window()->MaybeShowNewBackShortcutBubble(false);
+      break;
     case IDC_BACK:
+      browser_->window()->HideNewBackShortcutBubble();
       GoBack(browser_, disposition);
       break;
     case IDC_BACKSPACE_FORWARD:
-      if (!base::FeatureList::IsEnabled(kBackspaceGoesBackFeature)) {
-        browser_->window()->ShowNewBackShortcutBubble(true);
-        break;
-      }
-      // FALL THROUGH
+      if (base::FeatureList::IsEnabled(kBackspaceGoesBackFeature))
+        GoForward(browser_, disposition);
+      else
+        browser_->window()->MaybeShowNewBackShortcutBubble(true);
+      break;
     case IDC_FORWARD:
+      browser_->window()->HideNewBackShortcutBubble();
       GoForward(browser_, disposition);
       break;
     case IDC_RELOAD: