Avoid disk reads in TabPersistentStore for max tab_id.

chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/RestoreMigrateTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/RestoreMigrateTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/RestoreMigrateTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/RestoreMigrateTest.java
index c7857abe7a9f824a229fd1ccae18fd88e0f2832a..1e6c4324875525e62fb01d7b807e5e5b2fa05574 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/RestoreMigrateTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/RestoreMigrateTest.java
@@ -12,6 +12,8 @@ import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.browser.TabState;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tab.TabIdManager;
 import org.chromium.chrome.test.util.ApplicationData;
 import org.chromium.chrome.test.util.browser.tabmodel.MockTabModelSelector;
 
@@ -234,7 +236,9 @@ public class RestoreMigrateTest extends InstrumentationTestCase {
 
         int maxId = Math.max(getMaxId(selector0), getMaxId(selector1));
         RecordHistogram.disableForTests();
-        assertEquals("Invalid next id", maxId + 1, storeIn.loadStateInternal());
+        storeIn.loadState();
+        assertEquals("Invalid next id", maxId + 1,
+                TabIdManager.getInstance().generateValidId(Tab.INVALID_TAB_ID));
     }
 
     /**
@@ -261,8 +265,8 @@ public class RestoreMigrateTest extends InstrumentationTestCase {
                 getInstrumentation().getTargetContext(), null, null);
 
         RecordHistogram.disableForTests();
-        storeIn0.loadStateInternal();
-        storeIn1.loadStateInternal();
+        storeIn0.loadState();
+        storeIn1.loadState();
 
         assertEquals("Unexpected number of tabs to load", 6, storeIn0.getRestoredTabCount());
         assertEquals("Unexpected number of tabst o load", 3, storeIn1.getRestoredTabCount());