Reland "[DevUI DFM] Change install flow to use NavigationThrottle."

This reverts commit 168860e.

Reason for reland: Fixed problem: The target source_set("dev_ui_loader")
had missing dependencies, and doesn't reach.
  third_party/blink/public/mojom:mojom_platform
Two ways to fix this are:
  A: Add the missing dependencies to chrome/browser/dev_ui/android:dev_ui_loader
  B: Remove chrome/browser/dev_ui/android:dev_ui_loader, and fold its
     {sources, deps} into chrome/browser:browser.
We're choosing B for simplicity, but may adopt A eventually.

Original change's description:
> Revert "[DevUI DFM] Change install flow to use NavigationThrottle."
>
> Reason for revert: Seems to have broken android-archive-rel compile, though this may be exposing some pre-existing bad dependency elsewhere: https://ci.chromium.org/p/chromium/builders/ci/android-archive-rel/5717
>
> Change-Id: I7eff36d7e01c31a76f39250a255d27972b0962d9
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1864392
> Commit-Queue: Peter Kasting <pkasting@chromium.org>

> Original change's description:
> > [DevUI DFM] Change install flow to use NavigationThrottle.
> >
> > Bug: 927131,987040,1013522
> > Change-Id: I5c384671c858d26a303afc58c03f4314c8ef0117
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854524
> > Commit-Queue: Samuel Huang <huangs@chromium.org>

TBR=pkasting@chromium.org,creis@chromium.org,huangs@chromium.org,thestig@chromium.org,dbeam@chromium.org,agrieve@chromium.org,tiborg@chromium.org

Bug: 927131, 987040, 1013522
Change-Id: I526f3194b0115171721a53fca60fa6ffa6e3c441
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1864411
Reviewed-by: Samuel Huang <huangs@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706514}

chrome/android/modules/dev_ui/provider/dev_ui_module_provider.cc

@@ -12,24 +12,28 @@
 
 namespace dev_ui {
 
-// static
-DevUiModuleProvider* DevUiModuleProvider::test_instance_ = nullptr;
+namespace {
+
+// Global DevUiModuleProvider instance for testing.
+DevUiModuleProvider* g_test_instance = nullptr;
+
+}  // namespace
 
 // Destructor is public to enable management by std::unique_ptr<>.
 DevUiModuleProvider::~DevUiModuleProvider() = default;
 
 // static
 DevUiModuleProvider* DevUiModuleProvider::GetInstance() {
-  if (test_instance_)
-    return test_instance_;
+  if (g_test_instance)
+    return g_test_instance;
 
   static DevUiModuleProvider instance;
   return &instance;
 }
 
 // static
 void DevUiModuleProvider::SetTestInstance(DevUiModuleProvider* test_instance) {
-  test_instance_ = test_instance;
+  g_test_instance = test_instance;
 }
 
 bool DevUiModuleProvider::ModuleInstalled() {

chrome/android/modules/dev_ui/provider/dev_ui_module_provider.h

@@ -14,30 +14,27 @@ class DevUiModuleProvider {
   // Returns the singleton, which can be overridden using SetTestInstance().
   static DevUiModuleProvider* GetInstance();
 
-  // Overrides the singleton with caller-owned |test_instance|. Caller tests
+  // Overrides the singleton with caller-owned |test_instance|. Callers in tests
   // are responsible for resetting this to null on cleanup.
   static void SetTestInstance(DevUiModuleProvider* test_instance);
 
-  // Returns true if the DevUI module is installed.
+  // Returns true if the DevUI module is installed. Virtual to enable testing.
   virtual bool ModuleInstalled();
 
   // Asynchronously requests to install the DevUI module. |on_complete| is
   // called after the module install is completed, and takes a bool to indicate
-  // whether module install is successful.
+  // whether module install is successful. Virtual to enable testing.
   virtual void InstallModule(base::OnceCallback<void(bool)> on_complete);
 
   // Assuming that the DevUI module is installed, loads DevUI resources if not
-  // already loaded.
+  // already loaded. Virtual to enable testing.
   virtual void LoadModule();
 
  protected:
   DevUiModuleProvider();
   virtual ~DevUiModuleProvider();
   DevUiModuleProvider(const DevUiModuleProvider&) = delete;
   DevUiModuleProvider& operator=(const DevUiModuleProvider&) = delete;
-
- private:
-  static DevUiModuleProvider* test_instance_;
 };
 
 }  // namespace dev_ui

chrome/browser/BUILD.gn

@@ -2911,13 +2911,12 @@ jumbo_split_static_library("browser") {
     }
 
     if (dfmify_dev_ui) {
+      # TODO(huangs): Extracting this to a separate target.
       sources += [
-        "android/dev_ui/dev_ui_url_handler.cc",
-        "android/dev_ui/dev_ui_url_handler.h",
-        "ui/webui/android/dev_ui_loader/dev_ui_loader_message_handler.cc",
-        "ui/webui/android/dev_ui_loader/dev_ui_loader_message_handler.h",
-        "ui/webui/android/dev_ui_loader/dev_ui_loader_ui.cc",
-        "ui/webui/android/dev_ui_loader/dev_ui_loader_ui.h",
+        "dev_ui/android/dev_ui_loader_error_page.cc",
+        "dev_ui/android/dev_ui_loader_error_page.h",
+        "dev_ui/android/dev_ui_loader_throttle.cc",
+        "dev_ui/android/dev_ui_loader_throttle.h",
       ]
       deps += [ "//chrome/android/modules/dev_ui/provider:native" ]
     }

chrome/browser/browser_resources.grd

@@ -171,6 +171,7 @@
       <include name="IDR_TRANSLATE_INTERNALS_JS" file="../../components/translate/translate_internals/translate_internals.js" flattenhtml="true" compress="gzip" type="BINDATA" />
       <include name="IDR_FEEDBACK_MANIFEST" file="resources\feedback\manifest.json" type="BINDATA" />
       <if expr="is_android">
+        <include name="IDR_DEV_UI_LOADER_ERROR_HTML" file="resources/dev_ui/dev_ui_loader_error.html" compress="gzip" type="BINDATA" />
         <include name="IDR_EXPLORE_SITES_INTERNALS_HTML" file="resources\explore_sites_internals\explore_sites_internals.html" allowexternalscript="true" compress="gzip" type="BINDATA" />
         <include name="IDR_EXPLORE_SITES_INTERNALS_CSS" file="resources\explore_sites_internals\explore_sites_internals.css" compress="gzip" type="BINDATA" />
         <include name="IDR_EXPLORE_SITES_INTERNALS_JS" file="resources\explore_sites_internals\explore_sites_internals.js" compress="gzip" type="BINDATA" />
@@ -187,7 +188,6 @@
         <include name="IDR_SNIPPETS_INTERNALS_CSS" file="resources\snippets_internals\snippets_internals.css" compress="gzip" type="BINDATA" />
         <include name="IDR_SNIPPETS_INTERNALS_JS" file="resources\snippets_internals\snippets_internals.js" compress="gzip" type="BINDATA" />
         <include name="IDR_SNIPPETS_INTERNALS_MOJOM_LITE_JS" file="${root_gen_dir}\chrome\browser\ui\webui\snippets_internals\snippets_internals.mojom-lite.js" use_base_dir="false" type="BINDATA" compress="gzip" />
-        <part file="resources/dev_ui_loader/dev_ui_loader.grdp" />
       </if>
 
       <if expr="enable_supervised_users">

chrome/browser/chrome_content_browser_client.cc

@@ -415,7 +415,7 @@
 #include "ui/base/resource/resource_bundle_android.h"
 #include "ui/base/ui_base_paths.h"
 #if BUILDFLAG(DFMIFY_DEV_UI)
-#include "chrome/browser/android/dev_ui/dev_ui_url_handler.h"
+#include "chrome/browser/dev_ui/android/dev_ui_loader_throttle.h"
 #endif  // BUILDFLAG(DFMIFY_DEV_UI)
 #elif defined(OS_POSIX)
 #include "chrome/browser/chrome_browser_main_posix.h"
@@ -3349,12 +3349,6 @@ void ChromeContentBrowserClient::BrowserURLHandlerCreated(
   // Handler to rewrite chrome://newtab on Android.
   handler->AddHandlerPair(&chrome::android::HandleAndroidNativePageURL,
                           BrowserURLHandler::null_handler());
-#if BUILDFLAG(DFMIFY_DEV_UI)
-  // Handler to rewrite chrome:// URLs in the DevUI DFM, if not installed.
-  handler->AddHandlerPair(&chrome::android::HandleDfmifiedDevUiPageURL,
-                          BrowserURLHandler::null_handler());
-#endif  // BUILDFLAG(DFMIFY_DEV_UI)
-
 #else   // defined(OS_ANDROID)
   // Handler to rewrite chrome://newtab for InstantExtended.
   handler->AddHandlerPair(&search::HandleNewTabURLRewrite,
@@ -3832,6 +3826,14 @@ ChromeContentBrowserClient::CreateThrottlesForNavigation(
             handle, navigation_interception::SynchronyMode::kAsync));
   }
   throttles.push_back(InterceptOMADownloadNavigationThrottle::Create(handle));
+
+#if BUILDFLAG(DFMIFY_DEV_UI)
+  // If the DevUI DFM is already installed, then this is a no-op, except for the
+  // side effect of ensuring that the DevUI DFM is loaded.
+  MaybeAddThrottle(&throttles,
+                   dev_ui::DevUiLoaderThrottle::MaybeCreateThrottleFor(handle));
+#endif  // BUILDFLAG(DFMIFY_DEV_UI)
+
 #elif BUILDFLAG(ENABLE_EXTENSIONS)
   if (handle->IsInMainFrame()) {
     // Redirect some navigations to apps that have registered matching URL

chrome/browser/dev_ui/OWNERS

@@ -0,0 +1,2 @@
+huangs@chromium.org
+tiborg@chromium.org

chrome/browser/dev_ui/android/dev_ui_loader_error_page.cc

@@ -0,0 +1,33 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/dev_ui/android/dev_ui_loader_error_page.h"
+
+#include "chrome/grit/browser_resources.h"
+#include "components/strings/grit/components_strings.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/base/template_expressions.h"
+#include "ui/strings/grit/ui_strings.h"
+
+namespace dev_ui {
+
+std::string BuildErrorPageHtml() {
+  ui::TemplateReplacements replacements;
+  replacements["h1"] =
+      l10n_util::GetStringUTF8(IDS_DEV_UI_LOADER_ERROR_HEADING);
+  replacements["p"] =
+      l10n_util::GetStringUTF8(IDS_ERRORPAGES_SUGGESTION_LIST_HEADER);
+  replacements["li-1"] =
+      l10n_util::GetStringUTF8(IDS_DEV_UI_LOADER_ERROR_SUGGEST_RELOAD);
+  replacements["li-2"] =
+      l10n_util::GetStringUTF8(IDS_DEV_UI_LOADER_ERROR_SUGGEST_CHECK_INTERNET);
+
+  std::string source =
+      ui::ResourceBundle::GetSharedInstance().DecompressDataResource(
+          IDR_DEV_UI_LOADER_ERROR_HTML);
+  return ui::ReplaceTemplateExpressions(source, replacements);
+}
+
+}  // namespace dev_ui

chrome/browser/dev_ui/android/dev_ui_loader_error_page.h

@@ -0,0 +1,16 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_DEV_UI_ANDROID_DEV_UI_LOADER_ERROR_PAGE_H_
+#define CHROME_BROWSER_DEV_UI_ANDROID_DEV_UI_LOADER_ERROR_PAGE_H_
+
+#include <string>
+
+namespace dev_ui {
+
+std::string BuildErrorPageHtml();
+
+}  // namespace dev_ui
+
+#endif  // CHROME_BROWSER_DEV_UI_ANDROID_DEV_UI_LOADER_ERROR_PAGE_H_

chrome/browser/android/dev_ui/dev_ui_url_handler.cc → chrome/browser/dev_ui/android/dev_ui_loader_throttle.cc

@@ -2,15 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/android/dev_ui/dev_ui_url_handler.h"
+#include "chrome/browser/dev_ui/android/dev_ui_loader_throttle.h"
 
 #include <string>
+#include <utility>
 
+#include "base/logging.h"
 #include "chrome/android/modules/dev_ui/provider/dev_ui_module_provider.h"
+#include "chrome/browser/dev_ui/android/dev_ui_loader_error_page.h"
 #include "chrome/common/webui_url_constants.h"
 #include "components/safe_browsing/web_ui/constants.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_handle.h"
 #include "content/public/common/url_constants.h"
-#include "net/base/url_util.h"
+#include "net/base/net_errors.h"
 #include "url/gurl.h"
 
 namespace {
@@ -71,30 +76,65 @@ bool IsWebUiHostInDevUiDfm(const std::string& host) {
 
 }  // namespace
 
-namespace chrome {
-namespace android {
+namespace dev_ui {
 
-bool HandleDfmifiedDevUiPageURL(
-    GURL* url,
-    content::BrowserContext* /* browser_context */) {
-  if (!url->SchemeIs(content::kChromeUIScheme) ||
-      !IsWebUiHostInDevUiDfm(url->host())) {
-    return false;
-  }
+// static
+bool DevUiLoaderThrottle::ShouldInstallDevUiDfm(const GURL& url) {
+  return url.SchemeIs(content::kChromeUIScheme) &&
+         IsWebUiHostInDevUiDfm(url.host());
+}
+
+// static
+std::unique_ptr<content::NavigationThrottle>
+DevUiLoaderThrottle::MaybeCreateThrottleFor(content::NavigationHandle* handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(handle);
+  if (!handle->IsInMainFrame())
+    return nullptr;
+
+  if (!ShouldInstallDevUiDfm(handle->GetURL()))
+    return nullptr;
 
   // If module is already installed, ensure that it is loaded.
   if (dev_ui::DevUiModuleProvider::GetInstance()->ModuleInstalled()) {
     // Synchronously load module (if not already loaded).
     dev_ui::DevUiModuleProvider::GetInstance()->LoadModule();
-    return false;
+    return nullptr;
+  }
+
+  return std::make_unique<DevUiLoaderThrottle>(handle);
+}
+
+DevUiLoaderThrottle::DevUiLoaderThrottle(
+    content::NavigationHandle* navigation_handle)
+    : content::NavigationThrottle(navigation_handle) {}
+
+DevUiLoaderThrottle::~DevUiLoaderThrottle() = default;
+
+const char* DevUiLoaderThrottle::GetNameForLogging() {
+  return "DevUiLoaderThrottle";
+}
+
+content::NavigationThrottle::ThrottleCheckResult
+DevUiLoaderThrottle::WillStartRequest() {
+  if (!dev_ui::DevUiModuleProvider::GetInstance()->ModuleInstalled()) {
+    // Can handle multiple install requests.
+    dev_ui::DevUiModuleProvider::GetInstance()->InstallModule(
+        base::BindOnce(&DevUiLoaderThrottle::OnDevUiDfmInstallWithStatus,
+                       weak_ptr_factory_.GetWeakPtr()));
+    return DEFER;
+  }
+  return PROCEED;
+}
+
+void DevUiLoaderThrottle::OnDevUiDfmInstallWithStatus(bool success) {
+  if (success) {
+    dev_ui::DevUiModuleProvider::GetInstance()->LoadModule();
+    Resume();
+  } else {
+    std::string html = BuildErrorPageHtml();
+    CancelDeferredNavigation({BLOCK_REQUEST, net::ERR_CONNECTION_FAILED, html});
   }
-  // Create URL to the DevUI loader with "?url=<escaped original URL>" so that
-  // after install, the loader can redirect to the original URL.
-  *url = net::AppendQueryParameter(
-      GURL(std::string(kChromeUIDevUiLoaderURL) + "dev_ui_loader.html"), "url",
-      url->spec());
-  return true;
 }
 
-}  // namespace android
-}  // namespace chrome
+}  // namespace dev_ui

chrome/browser/dev_ui/android/dev_ui_loader_throttle.h

@@ -0,0 +1,54 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_DEV_UI_ANDROID_DEV_UI_LOADER_THROTTLE_H_
+#define CHROME_BROWSER_DEV_UI_ANDROID_DEV_UI_LOADER_THROTTLE_H_
+
+#include <memory>
+
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/navigation_throttle.h"
+
+namespace content {
+class NavigationHandle;
+}  // namespace content
+
+class GURL;
+
+namespace dev_ui {
+
+// For DevUI page navigations, if the DevUI DFM is not installed then delay
+// navigation and perform installation. On success, resumes navigation. On
+// failure, displays error (retries install on refresh).
+class DevUiLoaderThrottle : public content::NavigationThrottle {
+ public:
+  // Determines whether visiting |url| should trigger DevUI DFM install.
+  static bool ShouldInstallDevUiDfm(const GURL& url);
+
+  // Creates a throttle if the DevUI DFM needs to be installed. If the DevUI DFM
+  // will be used, is installed, but is not loaded, then resource load takes
+  // place as a side effect.
+  static std::unique_ptr<content::NavigationThrottle> MaybeCreateThrottleFor(
+      content::NavigationHandle* handle);
+
+  explicit DevUiLoaderThrottle(content::NavigationHandle* navigation_handle);
+  ~DevUiLoaderThrottle() override;
+  DevUiLoaderThrottle(const DevUiLoaderThrottle&) = delete;
+  const DevUiLoaderThrottle& operator=(const DevUiLoaderThrottle&) = delete;
+
+  // content::NavigationThrottle:
+  const char* GetNameForLogging() override;
+  ThrottleCheckResult WillStartRequest() override;
+
+ private:
+  // Callback for dev_ui::DevUiModuleProvider::InstallModule().
+  void OnDevUiDfmInstallWithStatus(bool success);
+
+  // Factory for creating references in callbacks.
+  base::WeakPtrFactory<DevUiLoaderThrottle> weak_ptr_factory_{this};
+};
+
+}  // namespace dev_ui
+
+#endif  // CHROME_BROWSER_DEV_UI_ANDROID_DEV_UI_LOADER_THROTTLE_H_