Remove circular dependencies between gn targets.

Break the circular dependency between //ios/chrome/browser/tabs
and //ios/chrome/browser/snapshots by using TabIdTabHelper to
get the WebState unique identifier instead of using Tab.

Extract tab_id_tab_helper.{h,mm} to a separate target
//ios/chrome/browser/web:tab_id_tab_helper.

Bug: none
Change-Id: Ib8c194a8e80a58674e203aa7b48afb3a245709ef
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Reviewed-on: https://chromium-review.googlesource.com/839767Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#525969}

ios/chrome/browser/snapshots/BUILD.gn

@@ -3,62 +3,51 @@
 # found in the LICENSE file.
 
 source_set("snapshots") {
-  sources = [
+  public = [
     "lru_cache.h",
-    "lru_cache.mm",
     "snapshot_cache.h",
-    "snapshot_cache.mm",
     "snapshot_cache_factory.h",
-    "snapshot_cache_factory.mm",
     "snapshot_cache_internal.h",
     "snapshot_cache_observer.h",
     "snapshot_cache_web_state_list_observer.h",
-    "snapshot_cache_web_state_list_observer.mm",
     "snapshot_constants.h",
-    "snapshot_constants.mm",
     "snapshot_generator_delegate.h",
     "snapshot_overlay.h",
-    "snapshot_overlay.mm",
+    "snapshot_overlay_provider.h",
     "snapshot_tab_helper.h",
     "snapshots_util.h",
-    "snapshots_util.mm",
-  ]
-  deps = [
-    "//base",
-    "//components/infobars/core",
-    "//components/keyed_service/core",
-    "//components/keyed_service/ios",
-    "//ios/chrome/browser",
-    "//ios/chrome/browser/browser_state",
-    "//ios/chrome/browser/ui",
-    "//ios/chrome/browser/web_state_list",
-    "//ios/web",
   ]
-  libs = [ "QuartzCore.framework" ]
-  configs += [ "//build/config/compiler:enable_arc" ]
-}
-
-source_set("snapshots_internal") {
-  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
+    "lru_cache.mm",
+    "snapshot_cache.mm",
+    "snapshot_cache_factory.mm",
+    "snapshot_cache_web_state_list_observer.mm",
+    "snapshot_constants.mm",
     "snapshot_generator.h",
     "snapshot_generator.mm",
-    "snapshot_overlay_provider.h",
+    "snapshot_overlay.mm",
     "snapshot_tab_helper.mm",
+    "snapshots_util.mm",
   ]
   deps = [
-    ":snapshots",
     "//base",
+    "//components/infobars/core",
+    "//components/keyed_service/core",
+    "//components/keyed_service/ios",
+    "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state",
     "//ios/chrome/browser/infobars",
     "//ios/chrome/browser/ui",
-    "//ios/chrome/browser/web",
+    "//ios/chrome/browser/web:tab_id_tab_helper",
+    "//ios/chrome/browser/web_state_list",
     "//ios/web/public",
   ]
   libs = [
+    "QuartzCore.framework",
     "UIKit.framework",
     "WebKit.framework",
   ]
+  configs += [ "//build/config/compiler:enable_arc" ]
 }
 
 source_set("test_utils") {
@@ -84,7 +73,6 @@ source_set("unit_tests") {
   ]
   deps = [
     ":snapshots",
-    ":snapshots_internal",
     ":test_utils",
     "//base",
     "//ios/chrome/browser/browser_state:test_support",

ios/chrome/browser/snapshots/snapshot_cache_web_state_list_observer.mm

@@ -6,8 +6,7 @@
 
 #include "base/logging.h"
 #import "ios/chrome/browser/snapshots/snapshot_cache.h"
-#import "ios/chrome/browser/tabs/legacy_tab_helper.h"
-#import "ios/chrome/browser/tabs/tab.h"
+#import "ios/chrome/browser/web/tab_id_tab_helper.h"
 #import "ios/chrome/browser/web_state_list/web_state_list.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -35,12 +34,12 @@ void SnapshotCacheWebStateListObserver::WebStateActivatedAt(
   NSMutableSet<NSString*>* set = [NSMutableSet set];
   if (active_index > 0) {
     web::WebState* web_state = web_state_list->GetWebStateAt(active_index - 1);
-    [set addObject:LegacyTabHelper::GetTabForWebState(web_state).tabId];
+    [set addObject:TabIdTabHelper::FromWebState(web_state)->tab_id()];
   }
 
   if (active_index + 1 < web_state_list->count()) {
     web::WebState* web_state = web_state_list->GetWebStateAt(active_index + 1);
-    [set addObject:LegacyTabHelper::GetTabForWebState(web_state).tabId];
+    [set addObject:TabIdTabHelper::FromWebState(web_state)->tab_id()];
   }
 
   snapshot_cache_.pinnedIDs = [set copy];

ios/chrome/browser/tabs/BUILD.gn

@@ -34,7 +34,6 @@ source_set("tabs") {
   ]
   libs = [ "UIKit.framework" ]
   configs += [ "//build/config/compiler:enable_arc" ]
-  allow_circular_includes_from = [ "//ios/chrome/browser/snapshots" ]
 }
 
 source_set("tabs_internal") {
@@ -109,7 +108,6 @@ source_set("tabs_internal") {
     "//ios/chrome/browser/sessions",
     "//ios/chrome/browser/sessions:serialisation",
     "//ios/chrome/browser/snapshots",
-    "//ios/chrome/browser/snapshots:snapshots_internal",
     "//ios/chrome/browser/ssl",
     "//ios/chrome/browser/store_kit",
     "//ios/chrome/browser/sync",

ios/chrome/browser/ui/BUILD.gn

@@ -295,7 +295,6 @@ source_set("ui_internal") {
     "//ios/chrome/browser/sessions:serialisation",
     "//ios/chrome/browser/signin",
     "//ios/chrome/browser/snapshots",
-    "//ios/chrome/browser/snapshots:snapshots_internal",
     "//ios/chrome/browser/ssl",
     "//ios/chrome/browser/store_kit",
     "//ios/chrome/browser/tabs",
@@ -386,7 +385,6 @@ source_set("ui_internal") {
     "//ios/chrome/browser/ui/toolbar",
   ]
   allow_circular_includes_from = [
-    "//ios/chrome/browser/snapshots:snapshots_internal",
     "//ios/chrome/browser/ui/ntp:ntp_internal",
     "//ios/chrome/browser/ui/overscroll_actions",
     "//ios/chrome/browser/ui/stack_view",

ios/chrome/browser/web/BUILD.gn

@@ -31,8 +31,6 @@ source_set("web") {
     "repost_form_tab_helper.mm",
     "sad_tab_tab_helper.h",
     "sad_tab_tab_helper.mm",
-    "tab_id_tab_helper.h",
-    "tab_id_tab_helper.mm",
   ]
   deps = [
     ":tab_helper_delegates",
@@ -47,6 +45,21 @@ source_set("web") {
     "//ui/base",
     "//url",
   ]
+  public_deps = [
+    ":tab_id_tab_helper",
+  ]
+}
+
+source_set("tab_id_tab_helper") {
+  sources = [
+    "tab_id_tab_helper.h",
+    "tab_id_tab_helper.mm",
+  ]
+  deps = [
+    "//base",
+    "//ios/web/public",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
 }
 
 source_set("tab_helper_delegates") {