Fix PageActionIconView text colors

PwaIconView was the first PageActionIconView to make use of the label
functionality. This revealed two bugs in PageActionIconView:
 - The text color was hard coded as kColorId_LabelDisabledColor.
 - OnNativeThemeChanged() didn't call the superclass resulting in
   uninitialised values for LabelButton::button_state_colors_.

This CL fixes both issues.

Before: https://bugs.chromium.org/p/chromium/issues/attachment?aid=386810&signed_aid=781DgZbUS5lVNN4F1taohA==&inline=1
After: https://bugs.chromium.org/p/chromium/issues/attachment?aid=386811&signed_aid=n-KvGoW3qBU6UsD6x72gnA==&inline=1

Change-Id: I834b7720932bab5eff93892ea7026b8d6140a720
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1545431
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Auto-Submit: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#646643}

chrome/browser/ui/views/page_action/page_action_icon_view.cc

@@ -65,10 +65,13 @@ bool PageActionIconView::Update() {
   return false;
 }
 
+SkColor PageActionIconView::GetLabelColorForTesting() const {
+  return label()->enabled_color();
+}
+
 SkColor PageActionIconView::GetTextColor() const {
-  // Returns the color of the label shown during animation.
   return GetNativeTheme()->GetSystemColor(
-      ui::NativeTheme::kColorId_LabelDisabledColor);
+      ui::NativeTheme::kColorId_TextfieldDefaultColor);
 }
 
 void PageActionIconView::GetAccessibleNodeData(ui::AXNodeData* node_data) {
@@ -144,6 +147,7 @@ void PageActionIconView::ViewHierarchyChanged(
 }
 
 void PageActionIconView::OnNativeThemeChanged(const ui::NativeTheme* theme) {
+  IconLabelBubbleView::OnNativeThemeChanged(theme);
   UpdateIconImage();
 }
 

chrome/browser/ui/views/page_action/page_action_icon_view.h

@@ -59,6 +59,8 @@ class PageActionIconView : public IconLabelBubbleView {
   // Retrieve the text to be used for a tooltip or accessible name.
   virtual base::string16 GetTextForTooltipAndAccessibleName() const = 0;
 
+  SkColor GetLabelColorForTesting() const;
+
  protected:
   enum ExecuteSource {
     EXECUTE_SOURCE_MOUSE,

chrome/browser/ui/views/page_action/pwa_install_view_browsertest.cc

@@ -19,6 +19,7 @@
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/common/referrer.h"
 #include "services/network/public/cpp/network_switches.h"
+#include "ui/gfx/color_utils.h"
 
 class PwaInstallViewBrowserTest : public InProcessBrowserTest {
  public:
@@ -219,3 +220,22 @@ IN_PROC_BROWSER_TEST_F(PwaInstallViewBrowserTest,
   EXPECT_TRUE(pwa_install_view_->visible());
   EXPECT_TRUE(pwa_install_view_->is_animating_label());
 }
+
+// Tests that the icon label is visible against the omnibox background after the
+// native widget becomes active.
+IN_PROC_BROWSER_TEST_F(PwaInstallViewBrowserTest, TextContrast) {
+  NavigateToURL(GetInstallableAppURL());
+  ASSERT_TRUE(app_banner_manager_->WaitForInstallableCheck());
+  EXPECT_TRUE(pwa_install_view_->visible());
+  EXPECT_TRUE(pwa_install_view_->is_animating_label());
+
+  pwa_install_view_->GetWidget()->OnNativeWidgetActivationChanged(true);
+
+  BrowserView* browser_view = BrowserView::GetBrowserViewForBrowser(browser());
+  SkColor omnibox_background = browser_view->GetLocationBarView()->GetColor(
+      OmniboxPart::LOCATION_BAR_BACKGROUND);
+  SkColor label_color = pwa_install_view_->GetLabelColorForTesting();
+  EXPECT_EQ(SkColorGetA(label_color), SK_AlphaOPAQUE);
+  EXPECT_GT(color_utils::GetContrastRatio(omnibox_background, label_color),
+            color_utils::kMinimumReadableContrastRatio);
+}