Mac: Make autocomplete popup track autocomplete field resizes.

chrome/browser/autocomplete/autocomplete_popup_view_mac.mm

Index: chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
diff --git a/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm b/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
index f2a33d8785e7039e5eb41ea93682fc34c33be9fb..1a0d35cdf95c141edc5f4a0c751d705d6d1773fb 100644
--- a/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
+++ b/chrome/browser/autocomplete/autocomplete_popup_view_mac.mm
@@ -190,6 +190,10 @@ NSAttributedString* AutocompletePopupViewMac::MatchText(
 
 // Tell popup model via popup_view_ about the selected row.
 - (void)select:sender;
+
+// Resize the popup when the field's window resizes.
+- (void)windowDidResize:(NSNotification*)notification;
+
 @end
 
 AutocompletePopupViewMac::AutocompletePopupViewMac(
@@ -241,6 +245,13 @@ void AutocompletePopupViewMac::CreatePopupIfNeeded() {
     [matrix setTarget:matrix_target_];
     [matrix setAction:@selector(select:)];
     [popup_ setContentView:matrix];
+
+    // We need the popup to follow window resize.
+    NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
+    [nc addObserver:matrix_target_ 
+           selector:@selector(windowDidResize:) 
+               name:NSWindowDidResizeNotification 
+             object:[field_ window]];
   }
 }
 
@@ -254,6 +265,11 @@ void AutocompletePopupViewMac::UpdatePopupAppearance() {
     NSMatrix* matrix = [popup_ contentView];
     [matrix setTarget:nil];
 
+    NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
+    [nc removeObserver:matrix_target_
+                  name:NSWindowDidResizeNotification 
+                object:[field_ window]];
+
     popup_.reset(nil);
 
     return;
@@ -455,4 +471,14 @@ void AutocompletePopupViewMac::AcceptInput() {
   popup_view_->AcceptInput();
 }
 
+- (void)windowDidResize:(NSNotification*)notification {
+  DCHECK(popup_view_);
+
+  // TODO(shess): UpdatePopupAppearance() is called frequently, so it
+  // should be really cheap, but in this case we could probably make
+  // things even cheaper by refactoring between the popup-placement
+  // code and the matrix-population code.
+  popup_view_->UpdatePopupAppearance();
+}
+
 @end