Add launcherPage.hide() API.

This CL adds a launcherPage.hide() API which can be used by custom
launcher pages to implement custom hiding behavior. The API only works
if the custom launcher page is showing and does nothing otherwise.

BUG=481712

Review URL: https://codereview.chromium.org/1137503005

Cr-Commit-Position: refs/heads/master@{#330065}

chrome/browser/apps/custom_launcher_page_browsertest_views.cc

@@ -315,10 +315,11 @@ IN_PROC_BROWSER_TEST_F(CustomLauncherPageBrowserTest, LauncherPageSubpages) {
       contents_view->IsStateActive(app_list::AppListModel::STATE_START));
 }
 
-IN_PROC_BROWSER_TEST_F(CustomLauncherPageBrowserTest,
-                       LauncherPageShow) {
+IN_PROC_BROWSER_TEST_F(CustomLauncherPageBrowserTest, LauncherPageShowAndHide) {
   const base::string16 kLauncherPageShowScript =
       base::ASCIIToUTF16("chrome.launcherPage.show();");
+  const base::string16 kLauncherPageHideScript =
+      base::ASCIIToUTF16("hideCustomLauncherPage()");
 
   LoadAndLaunchPlatformApp(kCustomLauncherPagePath, "Launched");
   app_list::AppListView* app_list_view = GetAppListView();
@@ -362,6 +363,29 @@ IN_PROC_BROWSER_TEST_F(CustomLauncherPageBrowserTest,
     EXPECT_TRUE(contents_view->IsStateActive(
         app_list::AppListModel::STATE_CUSTOM_LAUNCHER_PAGE));
   }
+
+  // Ensure launcherPage.hide() hides the launcher page when it's showing.
+  {
+    ExtensionTestMessageListener listener("onPageProgressAt0", false);
+    custom_page_frame->ExecuteJavaScript(kLauncherPageHideScript);
+
+    listener.WaitUntilSatisfied();
+
+    EXPECT_TRUE(
+        contents_view->IsStateActive(app_list::AppListModel::STATE_START));
+  }
+
+  // Nothing should happen if hide() is called from the apps page.
+  {
+    contents_view->SetActiveState(app_list::AppListModel::STATE_APPS, false);
+
+    ExtensionTestMessageListener listener("launcherPageHidden", false);
+    custom_page_frame->ExecuteJavaScript(kLauncherPageHideScript);
+    listener.WaitUntilSatisfied();
+
+    EXPECT_TRUE(
+        contents_view->IsStateActive(app_list::AppListModel::STATE_APPS));
+  }
 }
 
 IN_PROC_BROWSER_TEST_F(CustomLauncherPageBrowserTest, LauncherPageSetEnabled) {

chrome/browser/extensions/api/launcher_page/launcher_page_api.cc

@@ -65,6 +65,19 @@ ExtensionFunction::ResponseAction LauncherPageShowFunction::Run() {
   return RespondNow(NoArguments());
 }
 
+LauncherPageHideFunction::LauncherPageHideFunction() {
+}
+
+ExtensionFunction::ResponseAction LauncherPageHideFunction::Run() {
+  chrome::HostDesktopType host_desktop =
+      chrome::GetHostDesktopTypeForNativeWindow(
+          GetAssociatedWebContents()->GetTopLevelNativeWindow());
+
+  AppListService::Get(host_desktop)->HideCustomLauncherPage();
+
+  return RespondNow(NoArguments());
+}
+
 LauncherPageSetEnabledFunction::LauncherPageSetEnabledFunction() {
 }
 

chrome/browser/extensions/api/launcher_page/launcher_page_api.h

@@ -65,6 +65,21 @@ class LauncherPageShowFunction : public UIThreadExtensionFunction {
   DISALLOW_COPY_AND_ASSIGN(LauncherPageShowFunction);
 };
 
+class LauncherPageHideFunction : public UIThreadExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("launcherPage.hide", LAUNCHERPAGE_HIDE);
+
+  LauncherPageHideFunction();
+
+ protected:
+  ~LauncherPageHideFunction() override {}
+
+  ResponseAction Run() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(LauncherPageHideFunction);
+};
+
 class LauncherPageSetEnabledFunction : public UIThreadExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("launcherPage.setEnabled",

chrome/browser/ui/app_list/app_list_service.h

@@ -100,6 +100,10 @@ class AppListService {
   // Shows the app list, and switches to the custom launcher page.
   virtual void ShowForCustomLauncherPage(Profile* profile) = 0;
 
+  // Hides the custom launcher page if it is currently being shown. Does nothing
+  // otherwise.
+  virtual void HideCustomLauncherPage() = 0;
+
   // Dismiss the app list.
   virtual void DismissAppList() = 0;
 

chrome/browser/ui/app_list/app_list_service_disabled.cc

@@ -35,6 +35,7 @@ class AppListServiceDisabled : public AppListService {
       Profile* profile,
       const scoped_refptr<content::SpeechRecognitionSessionPreamble>& preamble)
       override {}
+  void HideCustomLauncherPage() override {}
   void ShowForAppInstall(Profile* profile,
                          const std::string& extension_id,
                          bool start_discovery_tracking) override {}

chrome/browser/ui/app_list/app_list_service_mac.h

@@ -51,6 +51,7 @@ class AppListServiceMac : public AppListServiceImpl,
   void Init(Profile* initial_profile) override;
   void DismissAppList() override;
   void ShowForCustomLauncherPage(Profile* profile) override;
+  void HideCustomLauncherPage() override;
   bool IsAppListVisible() const override;
   void EnableAppList(Profile* initial_profile,
                      AppListEnableSource enable_source) override;

chrome/browser/ui/app_list/app_list_service_mac.mm

@@ -425,6 +425,10 @@ void AppListServiceMac::ShowForCustomLauncherPage(Profile* profile) {
   NOTIMPLEMENTED();
 }
 
+void AppListServiceMac::HideCustomLauncherPage() {
+  NOTIMPLEMENTED();
+}
+
 bool AppListServiceMac::IsAppListVisible() const {
   return [GetNativeWindow() isVisible] &&
       ![animation_controller_ isClosing];

chrome/browser/ui/app_list/app_list_service_unittest.cc

@@ -56,6 +56,7 @@ class TestingAppListServiceImpl : public AppListServiceImpl {
   }
 
   void ShowForCustomLauncherPage(Profile* profile) override {}
+  void HideCustomLauncherPage() override {}
 
   void DismissAppList() override { showing_for_profile_ = NULL; }
 

chrome/browser/ui/app_list/app_list_service_views.cc

@@ -49,6 +49,19 @@ void AppListServiceViews::ShowForCustomLauncherPage(Profile* profile) {
                          app_list::AppListModel::STATE_CUSTOM_LAUNCHER_PAGE);
 }
 
+void AppListServiceViews::HideCustomLauncherPage() {
+  if (!shower_.IsAppListVisible())
+    return;
+
+  app_list::ContentsView* contents_view =
+      shower_.app_list()->app_list_main_view()->contents_view();
+
+  if (contents_view->IsStateActive(
+          app_list::AppListModel::STATE_CUSTOM_LAUNCHER_PAGE)) {
+    contents_view->SetActiveState(app_list::AppListModel::STATE_START, true);
+  }
+}
+
 void AppListServiceViews::DismissAppList() {
   if (!can_dismiss_)
     return;

chrome/browser/ui/app_list/app_list_service_views.h

@@ -38,6 +38,7 @@ class AppListServiceViews : public AppListServiceImpl,
                          const std::string& extension_id,
                          bool start_discovery_tracking) override;
   void ShowForCustomLauncherPage(Profile* profile) override;
+  void HideCustomLauncherPage() override;
   void DismissAppList() override;
   bool IsAppListVisible() const override;
   gfx::NativeWindow GetAppListWindow() override;

chrome/browser/ui/ash/app_list/app_list_service_ash.cc

@@ -91,6 +91,20 @@ void AppListServiceAsh::ShowForCustomLauncherPage(Profile* /*profile*/) {
   ShowAndSwitchToState(app_list::AppListModel::STATE_CUSTOM_LAUNCHER_PAGE);
 }
 
+void AppListServiceAsh::HideCustomLauncherPage() {
+  app_list::AppListView* app_list_view =
+      ash::Shell::GetInstance()->GetAppListView();
+  if (!app_list_view)
+    return;
+
+  app_list::ContentsView* contents_view =
+      app_list_view->app_list_main_view()->contents_view();
+  if (contents_view->IsStateActive(
+          app_list::AppListModel::STATE_CUSTOM_LAUNCHER_PAGE)) {
+    contents_view->SetActiveState(app_list::AppListModel::STATE_START, true);
+  }
+}
+
 bool AppListServiceAsh::IsAppListVisible() const {
   return ash::Shell::GetInstance()->GetAppListTargetVisibility();
 }

chrome/browser/ui/ash/app_list/app_list_service_ash.h

@@ -44,6 +44,7 @@ class AppListServiceAsh : public AppListServiceImpl {
                          const std::string& extension_id,
                          bool start_discovery_tracking) override;
   void ShowForCustomLauncherPage(Profile* profile) override;
+  void HideCustomLauncherPage() override;
   bool IsAppListVisible() const override;
   void DismissAppList() override;
   void EnableAppList(Profile* initial_profile,

chrome/common/extensions/api/launcher_page.idl

@@ -7,6 +7,7 @@
 namespace launcherPage {
   callback PushSubpageCallback = void();
   callback ShowCallback = void();
+  callback HideCallback = void();
   callback SetEnabledCallback = void();
 
   interface Functions {
@@ -24,6 +25,9 @@ namespace launcherPage {
     // page.
     static void show(optional ShowCallback callback);
 
+    // Returns the launcher to the start page if the launcher page is showing.
+    static void hide(optional HideCallback callback);
+
     // Sets whether the launcher page is enabled in the launcher. If disabled,
     // the launcher page will not be shown when the area at the bottom of the
     // launcher is pressed.

chrome/test/data/extensions/platform_apps/custom_launcher_page/main.js

@@ -31,6 +31,12 @@ function enableCustomLauncherPage() {
   });
 }
 
+function hideCustomLauncherPage() {
+  chrome.launcherPage.hide(function() {
+      chrome.test.sendMessage('launcherPageHidden');
+  });
+}
+
 document.addEventListener('DOMContentLoaded', function() {
   chrome.test.sendMessage('Launched');
 });

extensions/browser/extension_function_histogram_value.h

@@ -1098,6 +1098,7 @@ enum HistogramValue {
   PASSWORDSPRIVATE_REMOVESAVEDPASSWORD,
   PASSWORDSPRIVATE_REMOVEPASSWORDEXCEPTION,
   PASSWORDSPRIVATE_GETPLAINTEXTPASSWORD,
+  LAUNCHERPAGE_HIDE,
   // Last entry: Add new entries above and ensure to update
   // tools/metrics/histograms/histograms.xml.
   ENUM_BOUNDARY

tools/metrics/histograms/histograms.xml

@@ -52345,6 +52345,7 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="1037" label="PASSWORDSPRIVATE_REMOVESAVEDPASSWORD"/>
   <int value="1038" label="PASSWORDSPRIVATE_REMOVEPASSWORDEXCEPTION"/>
   <int value="1039" label="PASSWORDSPRIVATE_GETPLAINTEXTPASSWORD"/>
+  <int value="1040" label="LAUNCHERPAGE_HIDE"/>
 </enum>
 
 <enum name="ExtensionInstallCause" type="int">