Fix extension icon container resizing getting stuck at 0

In BrowserActionsContainer::GetFlexRule() the width is clamped between
a min width and a max width. If the min width is > max width it should
still win. This CL ensures this behaviour in the boundary condition and
fixes a bug where resizing the extension icons in the toolbar to 0 would
not be able to be reversed.

Before: https://bugs.chromium.org/p/chromium/issues/attachment?aid=439709&signed_aid=C2ncXrrBkAc-NH_GjVaSmg==&inline=1
After: https://bugs.chromium.org/p/chromium/issues/attachment?aid=439710&signed_aid=9D3JktJW8DssKm2eMOvAYg==&inline=1

Bug: 1066337
Change-Id: I6602673fdefb84ee0a3c2b1eaa728238d3175573
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2128039
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Auto-Submit: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754806}

chrome/browser/ui/views/toolbar/browser_actions_container.cc

@@ -371,7 +371,6 @@ views::FlexRule BrowserActionsContainer::GetFlexRule() {
             static_cast<const BrowserActionsContainer*>(view);
         gfx::Size preferred_size = browser_actions->GetPreferredSize();
         if (maximum_size.width()) {
-          const int max_width = *maximum_size.width();
           int width;
           if (browser_actions->resizing() || browser_actions->animating()) {
             // When there are actions present, the floor on the size of the
@@ -379,14 +378,15 @@ views::FlexRule BrowserActionsContainer::GetFlexRule() {
             const int min_width = browser_actions->num_toolbar_actions() == 0
                                       ? 0
                                       : browser_actions->GetResizeAreaWidth();
-            // The ceiling on the value is the lesser of the preferred and
-            // available size.
+            // If the provided maximum width is too small even for |min_width|,
+            // |min_width| takes precedence.
+            const int max_width = std::max(min_width, *maximum_size.width());
             width = base::ClampToRange(preferred_size.width(), min_width,
                                        max_width);
           } else {
             // When not animating or resizing, the desired width should always
             // be based on the number of icons that can be displayed.
-            width = browser_actions->GetWidthForMaxWidth(max_width);
+            width = browser_actions->GetWidthForMaxWidth(*maximum_size.width());
           }
           preferred_size =
               gfx::Size(width, browser_actions->GetHeightForWidth(width));