Modularize TabModelSelectorTab(Model)Observer

These are utility observers in the .tabmodel package. This CL moves:
- TabModelSelectorTabObserver
- TabModelSelectorTabModelObserver
so that other modules can use them.

Bug: 1095169
Change-Id: I6859ab199234f4270054849d03bfaa20b99aa5a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2246782Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#778987}

chrome/android/chrome_java_sources.gni

@@ -1577,8 +1577,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorBase.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorImpl.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorProfileSupplier.java",
-  "java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabModelObserver.java",
-  "java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabObserver.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorUma.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabPersistencePolicy.java",
   "java/src/org/chromium/chrome/browser/tabmodel/TabPersistentStore.java",

chrome/android/features/keyboard_accessory/internal/BUILD.gn

@@ -18,6 +18,7 @@ android_library("internal_java") {
     "//chrome/browser/flags:java",
     "//chrome/browser/profiles/android:java",
     "//chrome/browser/tab:java",
+    "//chrome/browser/tabmodel:java",
     "//chrome/browser/ui/android/favicon:java",
     "//chrome/browser/util:java",
     "//components/autofill/android:autofill_java",

chrome/browser/tabmodel/BUILD.gn

@@ -18,11 +18,14 @@ android_library("java") {
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelObserver.java",
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelector.java",
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorObserver.java",
+    "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabModelObserver.java",
+    "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabObserver.java",
     "android/java/src/org/chromium/chrome/browser/tabmodel/TabModelUtils.java",
   ]
   deps = [
     "//base:base_java",
     "//chrome/browser/profiles/android:java",
     "//chrome/browser/tab:java",
+    "//content/public/android:content_java",
   ]
 }

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabModelObserver.java → chrome/browser/tabmodel/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabModelObserver.java

@@ -68,8 +68,7 @@ public class TabModelSelectorTabModelObserver implements TabModelObserver {
     /**
      * Notifies that the registration of the observers has been completed.
      */
-    protected void onRegistrationComplete() {
-    }
+    protected void onRegistrationComplete() {}
 
     /**
      * Destroys the observer and removes itself as a listener for Tab updates.

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabObserver.java → chrome/browser/tabmodel/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorTabObserver.java

@@ -21,7 +21,6 @@ import java.util.List;
  * Observer of tab changes for all tabs owned by a {@link TabModelSelector}.
  */
 public class TabModelSelectorTabObserver extends EmptyTabObserver {
-
     private final TabModelSelector mTabModelSelector;
     private final TabModelSelectorTabModelObserver mTabModelObserver;
     private final SparseArray<Tab> mTabsToClose = new SparseArray<>();