weblayer: preferred color scheme support

Read system setting and set preferred_color_scheme. Refactor code a bit
to mirror password_echo_enabled. Same as password_echo_enabled, check
system changes when fragment becomes foreground.

Bug: 1070701
Change-Id: Iafcbf6886f8d2f1be474d87759d546182be1562f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2153829Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760520}

weblayer/browser/browser_impl.cc

@@ -12,6 +12,7 @@
 #include "base/path_service.h"
 #include "components/base32/base32.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/common/web_preferences.h"
 #include "weblayer/browser/feature_list_creator.h"
 #include "weblayer/browser/persistence/browser_persister.h"
 #include "weblayer/browser/persistence/minimal_browser_persister.h"
@@ -209,12 +210,14 @@ std::vector<uint8_t> BrowserImpl::GetMinimalPersistenceState(
   return PersistMinimalState(this, max_size_in_bytes);
 }
 
-bool BrowserImpl::GetPasswordEchoEnabled() {
+void BrowserImpl::SetWebPreferences(content::WebPreferences* prefs) {
 #if defined(OS_ANDROID)
-  return Java_BrowserImpl_getPasswordEchoEnabled(AttachCurrentThread(),
-                                                 java_impl_);
-#else
-  return false;
+  prefs->password_echo_enabled = Java_BrowserImpl_getPasswordEchoEnabled(
+      AttachCurrentThread(), java_impl_);
+  prefs->preferred_color_scheme =
+      Java_BrowserImpl_getDarkThemeEnabled(AttachCurrentThread(), java_impl_)
+          ? blink::PreferredColorScheme::kDark
+          : blink::PreferredColorScheme::kLight;
 #endif
 }
 

weblayer/browser/browser_impl.h

@@ -23,6 +23,7 @@ class FilePath;
 
 namespace content {
 class WebContents;
+struct WebPreferences;
 }
 
 namespace weblayer {
@@ -100,6 +101,7 @@ class BrowserImpl : public Browser {
   }
 
   bool GetPasswordEchoEnabled();
+  void SetWebPreferences(content::WebPreferences* prefs);
 
   // Browser:
   Tab* AddTab(std::unique_ptr<Tab> tab) override;

weblayer/browser/content_browser_client_impl.cc

@@ -282,12 +282,13 @@ blink::UserAgentMetadata ContentBrowserClientImpl::GetUserAgentMetadata() {
 void ContentBrowserClientImpl::OverrideWebkitPrefs(
     content::RenderViewHost* render_view_host,
     content::WebPreferences* prefs) {
+  prefs->default_encoding = l10n_util::GetStringUTF8(IDS_DEFAULT_ENCODING);
+
   content::WebContents* web_contents =
       content::WebContents::FromRenderViewHost(render_view_host);
   TabImpl* tab = TabImpl::FromWebContents(web_contents);
-  prefs->fullscreen_supported = tab && tab->fullscreen_delegate();
-  prefs->password_echo_enabled = tab && tab->GetPasswordEchoEnabled();
-  prefs->default_encoding = l10n_util::GetStringUTF8(IDS_DEFAULT_ENCODING);
+  if (tab)
+    tab->SetWebPreferences(prefs);
 }
 
 mojo::Remote<network::mojom::NetworkContext>

weblayer/browser/java/org/chromium/weblayer_private/BrowserImpl.java

@@ -6,6 +6,7 @@ package org.chromium.weblayer_private;
 
 import android.content.Context;
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.os.Bundle;
 import android.os.RemoteException;
 import android.provider.Settings;
@@ -62,6 +63,7 @@ public class BrowserImpl extends IBrowser.Stub {
     private boolean mFragmentResumed;
     // Cache the value instead of querying system every time.
     private Boolean mPasswordEchoEnabled;
+    private Boolean mDarkThemeEnabled;
 
     // Created in the constructor from saved state and used in setClient().
     private PersistenceInfo mPersistenceInfo;
@@ -237,12 +239,21 @@ public class BrowserImpl extends IBrowser.Stub {
         new TabImpl(mProfile, mWindowAndroid, nativeTab);
     }
 
-    private void checkPasswordEchoEnabled() {
-        if (mPasswordEchoEnabled == null) return;
+    private void checkPreferences() {
+        boolean changed = false;
+        if (mPasswordEchoEnabled != null) {
             boolean oldEnabled = mPasswordEchoEnabled;
             mPasswordEchoEnabled = null;
             boolean newEnabled = getPasswordEchoEnabled();
-        if (oldEnabled != newEnabled) {
+            changed = changed || oldEnabled != newEnabled;
+        }
+        if (mDarkThemeEnabled != null) {
+            boolean oldEnabled = mDarkThemeEnabled;
+            mDarkThemeEnabled = null;
+            boolean newEnabled = getDarkThemeEnabled();
+            changed = changed || oldEnabled != newEnabled;
+        }
+        if (changed) {
             BrowserImplJni.get().webPreferencesChanged(mNativeBrowser);
         }
     }
@@ -259,6 +270,18 @@ public class BrowserImpl extends IBrowser.Stub {
         return mPasswordEchoEnabled;
     }
 
+    @CalledByNative
+    private boolean getDarkThemeEnabled() {
+        Context context = getContext();
+        if (context == null) return false;
+        if (mDarkThemeEnabled == null) {
+            int uiMode = context.getResources().getConfiguration().uiMode;
+            mDarkThemeEnabled =
+                    (uiMode & Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES;
+        }
+        return mDarkThemeEnabled;
+    }
+
     @CalledByNative
     private void onTabAdded(TabImpl tab) {
         tab.attachToBrowser(this);
@@ -398,7 +421,7 @@ public class BrowserImpl extends IBrowser.Stub {
         mFragmentStarted = true;
         BrowserImplJni.get().onFragmentStart(mNativeBrowser, this);
         updateAllTabs();
-        checkPasswordEchoEnabled();
+        checkPreferences();
     }
 
     public void onFragmentStop() {

weblayer/browser/tab_impl.cc

@@ -29,6 +29,7 @@
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/renderer_preferences_util.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/web_preferences.h"
 #include "third_party/blink/public/mojom/renderer_preferences.mojom.h"
 #include "ui/base/window_open_disposition.h"
 #include "weblayer/browser/autofill_client_impl.h"
@@ -342,8 +343,12 @@ void TabImpl::WebPreferencesChanged() {
   web_contents_->GetRenderViewHost()->OnWebkitPreferencesChanged();
 }
 
-bool TabImpl::GetPasswordEchoEnabled() {
-  return browser_ ? browser_->GetPasswordEchoEnabled() : false;
+void TabImpl::SetWebPreferences(content::WebPreferences* prefs) {
+  prefs->fullscreen_supported = !!fullscreen_delegate_;
+
+  if (!browser_)
+    return;
+  browser_->SetWebPreferences(prefs);
 }
 
 void TabImpl::OnLosingActive() {

weblayer/browser/tab_impl.h

@@ -32,6 +32,7 @@ class AutofillProvider;
 namespace content {
 class WebContents;
 struct ContextMenuParams;
+struct WebPreferences;
 }
 
 namespace sessions {
@@ -126,7 +127,6 @@ class TabImpl : public Tab,
 #endif
 
   ErrorPageDelegate* error_page_delegate() { return error_page_delegate_; }
-  FullscreenDelegate* fullscreen_delegate() { return fullscreen_delegate_; }
 
   // Tab:
   void SetErrorPageDelegate(ErrorPageDelegate* delegate) override;
@@ -144,7 +144,7 @@ class TabImpl : public Tab,
 #endif
 
   void WebPreferencesChanged();
-  bool GetPasswordEchoEnabled();
+  void SetWebPreferences(content::WebPreferences* prefs);
 
   // Executes |script| with a user gesture.
   void ExecuteScriptWithUserGestureForTests(const base::string16& script);