Start caching the theme color in web_contents

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index d47a6ef362c8157626ee30e86106e2604b0cfb80..82b0f43298cb507bcf6adc30aec8863c986a0465 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -341,6 +341,8 @@ WebContentsImpl::WebContentsImpl(BrowserContext* browser_context,
       upload_position_(0),
       displayed_insecure_content_(false),
       has_accessed_initial_document_(false),
+      theme_color_(SK_ColorTRANSPARENT),
+      last_sent_theme_color_(SK_ColorTRANSPARENT),
       capturer_count_(0),
       should_normally_be_visible_(true),
       is_being_destroyed_(false),
@@ -720,6 +722,10 @@ WebContentsView* WebContentsImpl::GetView() const {
   return view_.get();
 }
 
+SkColor WebContentsImpl::GetThemeColor() const {
+  return theme_color_;
+}
+
 void WebContentsImpl::SetAccessibilityMode(AccessibilityMode mode) {
   if (mode == accessibility_mode_)
     return;
@@ -2717,6 +2723,9 @@ void WebContentsImpl::DidNavigateMainFramePostCommit(
         static_cast<RenderWidgetHostViewBase*>(GetRenderWidgetHostView());
     if (rwhvb)
       rwhvb->OnDidNavigateMainFrameToNewPage();
+
+    // Reset theme color on navigation to new page.
+    theme_color_ = SK_ColorTRANSPARENT;
   }
 
   if (!details.is_in_page) {
@@ -2769,8 +2778,9 @@ bool WebContentsImpl::CanOverscrollContent() const {
 }
 
 void WebContentsImpl::OnThemeColorChanged(SkColor theme_color) {
-  FOR_EACH_OBSERVER(WebContentsObserver, observers_,
-                    DidChangeThemeColor(theme_color));
+  // Update the theme color. This is to be published to observers on visually
+  // non empty paint.
+  theme_color_ = theme_color;
 }
 
 void WebContentsImpl::OnDidLoadResourceFromMemoryCache(
@@ -3264,6 +3274,13 @@ void WebContentsImpl::OnMediaPausedNotification(int64 player_cookie) {
 void WebContentsImpl::OnFirstVisuallyNonEmptyPaint() {
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     DidFirstVisuallyNonEmptyPaint());
+
+  if (theme_color_ != last_sent_theme_color_) {
+    // Theme color should have updated by now if there was one.
+    FOR_EACH_OBSERVER(WebContentsObserver, observers_,
+                      DidChangeThemeColor(theme_color_));
+    last_sent_theme_color_ = theme_color_;
+  }
 }
 
 void WebContentsImpl::DidChangeVisibleSSLState() {