Always call WasShown() before trying to paint.

See the bug link for details on the crash that this CL is attempting to fix.
Although I haven't been able to reproduce the crash locally, my intuition is
that, when we call window->ShowInstant(), sometimes it tries to paint, and
since the RenderWidgetHostView hasn't yet been told that it's being shown, it
fails the DCHECK(). So, reorder the calls so that WasShown() is always called
before any change to the Instant overlay layout (ShowInstant/HideInstant).

BUG=143207
R=sky@chromium.org
TEST=Watch try bots/waterfall; Instant shouldn't fire this DCHECK().

Review URL: https://chromiumcodereview.appspot.com/10828374

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152348 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/instant/instant_browsertest.cc

@@ -583,8 +583,7 @@ IN_PROC_BROWSER_TEST_F(InstantTest, TransitionsBetweenSearchAndURL) {
 }
 
 // Test that Instant can't be fooled into committing a URL.
-// Disabled: http://crbug.com/143207
-IN_PROC_BROWSER_TEST_F(InstantTest, DISABLED_DoesNotCommitURLs) {
+IN_PROC_BROWSER_TEST_F(InstantTest, DoesNotCommitURLs) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant("instant.html"));
   EXPECT_TRUE(ui_test_utils::BringBrowserWindowToFront(browser()));
 

chrome/browser/ui/browser_instant_controller.cc

@@ -78,6 +78,7 @@ bool BrowserInstantController::OpenInstant(WindowOpenDisposition disposition) {
 
 void BrowserInstantController::ShowInstant() {
   TabContents* preview = instant_->GetPreviewContents();
+  preview->web_contents()->WasShown();
   browser_->window()->ShowInstant(preview);
 
   content::NotificationService::current()->Notify(
@@ -88,10 +89,12 @@ void BrowserInstantController::ShowInstant() {
   // TODO(beng): Investigate if we can avoid this and instead rely on the
   //             visibility of the WebContentsView.
   chrome::GetActiveWebContents(browser_)->WasHidden();
-  preview->web_contents()->WasShown();
 }
 
 void BrowserInstantController::HideInstant() {
+  if (chrome::GetActiveWebContents(browser_))
+    chrome::GetActiveWebContents(browser_)->WasShown();
+
   browser_->window()->HideInstant();
 
   content::NotificationService::current()->Notify(
@@ -99,8 +102,6 @@ void BrowserInstantController::HideInstant() {
       content::Source<InstantController>(instant()),
       content::NotificationService::NoDetails());
 
-  if (chrome::GetActiveWebContents(browser_))
-    chrome::GetActiveWebContents(browser_)->WasShown();
   if (TabContents* preview = instant_->GetPreviewContents())
     preview->web_contents()->WasHidden();
 }