Start caching the theme color in web_contents

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 2e0e9661e18fb0fa900b1255b2f7b500a070de69..5cc17b8082475b77f0a65065e02c18f423747160 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -224,6 +224,7 @@ class CONTENT_EXPORT WebContentsImpl
   int GetRoutingID() const override;
   RenderWidgetHostView* GetRenderWidgetHostView() const override;
   RenderWidgetHostView* GetFullscreenRenderWidgetHostView() const override;
+  SkColor GetThemeColor() const override;
   WebUI* CreateWebUI(const GURL& url) override;
   WebUI* GetWebUI() const override;
   WebUI* GetCommittedWebUI() const override;
@@ -1103,6 +1104,13 @@ class CONTENT_EXPORT WebContentsImpl
   // to modify the blank page.  Always false after the first commit.
   bool has_accessed_initial_document_;
 
+  // The theme color for the underlying document as specified
+  // by theme-color meta tag.
+  SkColor theme_color_;
+
+  // The last published theme color.
+  SkColor last_sent_theme_color_;
+
   // Data for misc internal state ----------------------------------------------
 
   // When > 0, the WebContents is currently being captured (e.g., for