app_shell: Fix focus on opening new app windows

app_shell is pure-aura, so cannot rely on the usual views::WebView and
views::Widget initial-focus behavior. It must manually set focus on the
WebContents during creation.

BUG=438751
TEST=added to app_shell_browsertests ShellApiTest

Review URL: https://codereview.chromium.org/754313003

Cr-Commit-Position: refs/heads/master@{#307040}

extensions/shell/browser/shell_app_delegate.cc

@@ -4,6 +4,7 @@
 
 #include "extensions/shell/browser/shell_app_delegate.h"
 
+#include "content/public/browser/web_contents.h"
 #include "extensions/common/constants.h"
 #include "extensions/shell/browser/media_capture_util.h"
 
@@ -16,6 +17,7 @@ ShellAppDelegate::~ShellAppDelegate() {
 }
 
 void ShellAppDelegate::InitWebContents(content::WebContents* web_contents) {
+  Observe(web_contents);
 }
 
 void ShellAppDelegate::ResizeWebContents(content::WebContents* web_contents,
@@ -92,4 +94,11 @@ void ShellAppDelegate::SetTerminatingCallback(const base::Closure& callback) {
   NOTIMPLEMENTED();
 }
 
+void ShellAppDelegate::RenderViewCreated(
+    content::RenderViewHost* render_view_host) {
+  // The views implementation of AppWindow takes focus via SetInitialFocus()
+  // and views::WebView but app_shell is aura-only and must do it manually.
+  web_contents()->Focus();
+}
+
 }  // namespace extensions

extensions/shell/browser/shell_app_delegate.h

@@ -6,11 +6,14 @@
 #define EXTENSIONS_SHELL_BROWSER_SHELL_APP_DELEGATE_H_
 
 #include "extensions/browser/app_window/app_delegate.h"
+#include "content/public/browser/web_contents_observer.h"
 
 namespace extensions {
 
-// app_shell's AppDelegate implementation.
-class ShellAppDelegate : public AppDelegate {
+// AppDelegate implementation for app_shell. Sets focus after the WebContents is
+// created. Ignores most operations that would create a new dialog or window.
+class ShellAppDelegate : public AppDelegate,
+                         public content::WebContentsObserver {
  public:
   ShellAppDelegate();
   ~ShellAppDelegate() override;
@@ -48,6 +51,9 @@ class ShellAppDelegate : public AppDelegate {
   bool IsWebContentsVisible(content::WebContents* web_contents) override;
   void SetTerminatingCallback(const base::Closure& callback) override;
 
+  // content::WebContentsObserver:
+  void RenderViewCreated(content::RenderViewHost* render_view_host) override;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ShellAppDelegate);
 };

extensions/shell/browser/shell_browsertest.cc

@@ -4,15 +4,27 @@
 
 #include "base/logging.h"
 #include "content/public/browser/notification_service.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/test/test_utils.h"
+#include "extensions/browser/app_window/app_window.h"
+#include "extensions/browser/app_window/app_window_registry.h"
 #include "extensions/browser/notification_types.h"
 #include "extensions/shell/test/shell_apitest.h"
+#include "ui/aura/window.h"
 
 namespace extensions {
 
 // Test that we can open an app window and wait for it to load.
 IN_PROC_BROWSER_TEST_F(ShellApiTest, Basic) {
   ASSERT_TRUE(RunAppTest("platform_app")) << message_;
+
+  // A window was created.
+  AppWindow* app_window =
+      AppWindowRegistry::Get(browser_context())->app_windows().front();
+  ASSERT_TRUE(app_window);
+
+  // The web contents have focus.
+  EXPECT_TRUE(app_window->web_contents()->GetContentNativeView()->HasFocus());
 }
 
 }  // namespace extensions