Convert SetVisuallyDeemphasized IPC to mojo

extensions/renderer/extensions_render_frame_observer.cc

Index: extensions/renderer/extensions_render_frame_observer.cc
diff --git a/extensions/renderer/extensions_render_frame_observer.cc b/extensions/renderer/extensions_render_frame_observer.cc
index be6dbccd2f1e12e36e90bbc7021516595a1dbbec..3d5d7c3b88a7e9e9a7247248b230a6a676a30cd7 100644
--- a/extensions/renderer/extensions_render_frame_observer.cc
+++ b/extensions/renderer/extensions_render_frame_observer.cc
@@ -9,9 +9,12 @@
 #include "base/strings/string_split.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_view.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/stack_frame.h"
+#include "services/service_manager/public/cpp/interface_registry.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebView.h"
 
 namespace extensions {
 
@@ -76,12 +79,32 @@ StackTrace GetStackTraceFromMessage(base::string16* message,
 
 ExtensionsRenderFrameObserver::ExtensionsRenderFrameObserver(
     content::RenderFrame* render_frame)
-    : content::RenderFrameObserver(render_frame) {
+    : content::RenderFrameObserver(render_frame),
+      webview_visually_deemphasized_(false) {
+  render_frame->GetInterfaceRegistry()->AddInterface(
+      base::Bind(&ExtensionsRenderFrameObserver::AssociateBindings,
+                 base::Unretained(this)));
 }
 
 ExtensionsRenderFrameObserver::~ExtensionsRenderFrameObserver() {
 }
 
+void ExtensionsRenderFrameObserver::AssociateBindings(

[Ken Rockot(use gerrit already), 2017/03/08 17:31:38]

nit: This is a pretty weird method name for what it does. Maybe just call it
BindAppWindowHandler or BindAppWindowHandlerRequest?

[catmullings, 2017/03/08 18:23:00]

Done.

+    mojom::AppWindowHandlerRequest request) {
+  bindings_.AddBinding(this, std::move(request));
+}
+
+void ExtensionsRenderFrameObserver::SetVisuallyDeemphasized(bool deemphasized) {
+  if (webview_visually_deemphasized_ == deemphasized)
+    return;
+
+  webview_visually_deemphasized_ = deemphasized;
+
+  SkColor color =
+      deemphasized ? SkColorSetARGB(178, 0, 0, 0) : SK_ColorTRANSPARENT;
+  render_frame()->GetRenderView()->GetWebView()->setPageOverlayColor(color);
+}
+
 void ExtensionsRenderFrameObserver::DetailedConsoleMessageAdded(
     const base::string16& message,
     const base::string16& source,