Add setting to isolate zoom changes by default.

chrome/browser/ui/tabs/tab_strip_model_unittest.cc

Index: chrome/browser/ui/tabs/tab_strip_model_unittest.cc
diff --git a/chrome/browser/ui/tabs/tab_strip_model_unittest.cc b/chrome/browser/ui/tabs/tab_strip_model_unittest.cc
index f040375f844bf6032b3b6167f6aa9f4a93631bdf..590d4dbacc617dddb5d3c2b7e839550c19936592 100644
--- a/chrome/browser/ui/tabs/tab_strip_model_unittest.cc
+++ b/chrome/browser/ui/tabs/tab_strip_model_unittest.cc
@@ -31,6 +31,7 @@
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
 #include "chrome/test/base/testing_profile.h"
 #include "components/web_modal/web_contents_modal_dialog_manager.h"
+#include "components/zoom/zoom_controller.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/render_process_host.h"
@@ -38,6 +39,7 @@
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/test/web_contents_tester.h"
 #include "extensions/common/extension.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::SiteInstance;
@@ -2124,6 +2126,42 @@ TEST_F(TabStripModelTest, ReplaceSendsSelected) {
   strip.CloseAllTabs();
 }
 
+namespace {
+class MockZoomController : public zoom::ZoomController {
+ public:
+  static void CreateForTesting(content::WebContents* contents) {
+    ASSERT_FALSE(zoom::ZoomController::FromWebContents(contents));
+    contents->SetUserData(UserDataKey(), new MockZoomController(contents));
+  }
+
+  explicit MockZoomController(content::WebContents* contents)
+      : zoom::ZoomController(contents) {}
+
+  MOCK_METHOD1(WebContentsReplaced, void(WebContents* new_contents));
+};
+}  // namespace
+
+// Makes sure the TabStripModel notifies the ZoomController during the
+// replacement of its WebContents.
+TEST_F(TabStripModelTest, ReplaceNotifiesZoomController) {
+  TabStripDummyDelegate delegate;
+  TabStripModel strip(&delegate, profile());
+
+  WebContents* contents1 = CreateWebContents();
+  WebContents* contents2 = CreateWebContents();
+  MockZoomController::CreateForTesting(contents1);
+  MockZoomController* mock_controller = static_cast<MockZoomController*>(
+      zoom::ZoomController::FromWebContents(contents1));
+  ASSERT_TRUE(mock_controller);
+
+  strip.AppendWebContents(contents1, true);
+
+  EXPECT_CALL(*mock_controller, WebContentsReplaced(contents2));
+  delete strip.ReplaceWebContentsAt(0, contents2);
+
+  strip.CloseAllTabs();
+}
+
 // Makes sure TabStripModel handles the case of deleting a tab while removing
 // another tab.
 TEST_F(TabStripModelTest, DeleteFromDestroy) {