chrome: remove kChromeUIThumbnailListHost

AFAICT it's no longer used.
I believe it was orphaned here:
https://codereview.chromium.org/1129903008 .

BUG=none
TEST=none

Change-Id: Ib47b4515e139d2ce0175ddb5ef13c5a88e726d78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2644103
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#846136}

chrome/browser/ui/browser_navigator.cc

@@ -771,7 +771,6 @@ bool IsHostAllowedInIncognito(const GURL& url) {
   if (scheme == chrome::kChromeSearchScheme) {
     return host != chrome::kChromeUIThumbnailHost &&
            host != chrome::kChromeUIThumbnailHost2 &&
-           host != chrome::kChromeUIThumbnailListHost &&
            host != chrome::kChromeUISuggestionsHost;
   }
 
@@ -805,7 +804,6 @@ bool IsHostAllowedInIncognito(const GURL& url) {
          host != chrome::kChromeUIBookmarksHost &&
          host != chrome::kChromeUIThumbnailHost &&
          host != chrome::kChromeUIThumbnailHost2 &&
-         host != chrome::kChromeUIThumbnailListHost &&
          host != chrome::kChromeUISuggestionsHost &&
          host != chrome::kChromeUIDevicesHost &&
          host != chrome::kChromeUINewTabPageHost;

chrome/common/webui_url_constants.cc

@@ -172,7 +172,6 @@ const char kChromeUITopChromeDomain[] = "top-chrome";
 const char kChromeUIUntrustedThemeURL[] = "chrome-untrusted://theme/";
 const char kChromeUIThumbnailHost2[] = "thumb2";
 const char kChromeUIThumbnailHost[] = "thumb";
-const char kChromeUIThumbnailListHost[] = "thumbnails";
 const char kChromeUIThumbnailURL[] = "chrome://thumb/";
 const char kChromeUITranslateInternalsHost[] = "translate-internals";
 const char kChromeUIUsbInternalsHost[] = "usb-internals";
@@ -501,7 +500,6 @@ const char* const kChromeHostURLs[] = {
     kChromeUISyncInternalsHost,
 #if !defined(OS_ANDROID)
     kChromeUITermsHost,
-    kChromeUIThumbnailListHost,
 #endif
     kChromeUITranslateInternalsHost,
     kChromeUIUsbInternalsHost,

chrome/common/webui_url_constants.h

@@ -171,7 +171,6 @@ extern const char kChromeUITopChromeDomain[];
 extern const char kChromeUIUntrustedThemeURL[];
 extern const char kChromeUIThumbnailHost2[];
 extern const char kChromeUIThumbnailHost[];
-extern const char kChromeUIThumbnailListHost[];
 extern const char kChromeUIThumbnailURL[];
 extern const char kChromeUITranslateInternalsHost[];
 extern const char kChromeUIUsbInternalsHost[];