Tab Search: Fix recursive paint in TabSearchButton

This CL fixes a recursive paint bug in the TabSearchButton. Currently
SetImage() is called within PaintIcon(). This causes a paint
recursion as SetImage() will schedule a paint after it has been set.

This CL moves the SetImage() call into the FrameColorsChanged()
method to fix the issue.

Bug: 1121276
Change-Id: I89e10d17bf69d757112ea8655c79191a7541d18d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2375933
Commit-Queue: Thomas Lukaszewicz <tluk@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801533}

chrome/browser/ui/views/tabs/new_tab_button.h

@@ -37,7 +37,7 @@ class NewTabButton : public views::ImageButton,
   // Called when the tab strip transitions to/from single tab mode, the frame
   // state changes or the accent color changes.  Updates the glyph colors for
   // the best contrast on the background.
-  void FrameColorsChanged();
+  virtual void FrameColorsChanged();
 
   void AnimateInkDropToStateForTesting(views::InkDropState state);
 

chrome/browser/ui/views/tabs/tab_search_button.cc

@@ -41,6 +41,16 @@ TabSearchButton::TabSearchButton(TabStrip* tab_strip,
 
 TabSearchButton::~TabSearchButton() = default;
 
+void TabSearchButton::FrameColorsChanged() {
+  NewTabButton::FrameColorsChanged();
+  // Icon color needs to be updated here as this is called when the hosting
+  // window switches between active and inactive states. In each state the
+  // foreground color of the tab controls is expected to change.
+  SetImage(
+      Button::STATE_NORMAL,
+      gfx::CreateVectorIcon(kCaretDownIcon, kIconSize, GetForegroundColor()));
+}
+
 void TabSearchButton::ButtonPressed(views::Button* sender,
                                     const ui::Event& event) {
   if (bubble_)
@@ -64,11 +74,7 @@ void TabSearchButton::OnWidgetClosing(views::Widget* widget) {
 }
 
 void TabSearchButton::PaintIcon(gfx::Canvas* canvas) {
-  // Icon color needs to be updated here as this is called when the hosting
-  // window switches between active and incactive states. In each state the
-  // foreground color of the tab controls is expected to change.
-  SetImage(
-      Button::STATE_NORMAL,
-      gfx::CreateVectorIcon(kCaretDownIcon, kIconSize, GetForegroundColor()));
+  // Call ImageButton::PaintButtonContents() to paint the TabSearchButton's
+  // VectorIcon.
   views::ImageButton::PaintButtonContents(canvas);
 }

chrome/browser/ui/views/tabs/tab_search_button.h

@@ -36,6 +36,9 @@ class TabSearchButton : public NewTabButton,
   TabSearchButton& operator=(const TabSearchButton&) = delete;
   ~TabSearchButton() override;
 
+  // NewTabButton:
+  void FrameColorsChanged() override;
+
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;