make extension apis tolerate browser absence during start-up & shutdown

Note: I was never able to directly reproduce the 13082 bug, the error mode is clear (there was no selected tab during a call to tabs.getSelected()). This fix will address that issue and we should stop seeing this crash reports.

R=erikkay
BUG=13082

Review URL: http://codereview.chromium.org/119117

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@17631 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 63 insertions, 30 deletions

diff --git a/chrome/browser/extensions/extension_function_dispatcher.cc b/chrome/browser/extensions/extension_function_dispatcher.cc
index dc5c8f1..93a34db 100644
--- a/chrome/browser/extensions/extension_function_dispatcher.cc
+++ b/chrome/browser/extensions/extension_function_dispatcher.cc
@@ -68,7 +68,7 @@ void FactoryRegistry::ResetFunctions() {
   namespace bookmarks = extension_bookmarks_module_constants;
 
   // Windows
-  factories_[tabs::kGetWindowFunction] = 
+  factories_[tabs::kGetWindowFunction] =
       &NewExtensionFunction<GetWindowFunction>;
   factories_[tabs::kGetCurrentWindowFunction] =
       &NewExtensionFunction<GetCurrentWindowFunction>;
@@ -76,27 +76,27 @@ void FactoryRegistry::ResetFunctions() {
       &NewExtensionFunction<GetLastFocusedWindowFunction>;
   factories_[tabs::kGetAllWindowsFunction] =
       &NewExtensionFunction<GetAllWindowsFunction>;
-  factories_[tabs::kCreateWindowFunction] = 
+  factories_[tabs::kCreateWindowFunction] =
       &NewExtensionFunction<CreateWindowFunction>;
-  factories_[tabs::kUpdateWindowFunction] = 
+  factories_[tabs::kUpdateWindowFunction] =
       &NewExtensionFunction<UpdateWindowFunction>;
-  factories_[tabs::kRemoveWindowFunction] = 
+  factories_[tabs::kRemoveWindowFunction] =
       &NewExtensionFunction<RemoveWindowFunction>;
 
   // Tabs
-  factories_[tabs::kGetTabFunction] = 
+  factories_[tabs::kGetTabFunction] =
       &NewExtensionFunction<GetTabFunction>;
   factories_[tabs::kGetSelectedTabFunction] =
       &NewExtensionFunction<GetSelectedTabFunction>;
   factories_[tabs::kGetAllTabsInWindowFunction] =
       &NewExtensionFunction<GetAllTabsInWindowFunction>;
-  factories_[tabs::kCreateTabFunction] = 
+  factories_[tabs::kCreateTabFunction] =
       &NewExtensionFunction<CreateTabFunction>;
-  factories_[tabs::kUpdateTabFunction] = 
+  factories_[tabs::kUpdateTabFunction] =
       &NewExtensionFunction<UpdateTabFunction>;
-  factories_[tabs::kMoveTabFunction] = 
+  factories_[tabs::kMoveTabFunction] =
       &NewExtensionFunction<MoveTabFunction>;
-  factories_[tabs::kRemoveTabFunction] = 
+  factories_[tabs::kRemoveTabFunction] =
       &NewExtensionFunction<RemoveTabFunction>;
 
   // Page Actions.
@@ -185,7 +185,6 @@ Browser* ExtensionFunctionDispatcher::GetBrowser() {
   DCHECK(delegate_);
 
   Browser* retval = delegate_->GetBrowser();
-  DCHECK(retval);
   return retval;
 }
 
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index 741c9fc..9509577 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -132,9 +132,13 @@ void ExtensionHost::ShowCreatedWindow(int route_id,
                                       const GURL& creator_url) {
   TabContents* contents = delegate_view_helper_.GetCreatedWindow(route_id);
   if (contents) {
+    Browser* browser = GetBrowser();
+    DCHECK(browser);
+    if (!browser)
+      return;
     // TODO(erikkay) is it safe to pass in NULL as source?
-    GetBrowser()->AddTabContents(contents, disposition, initial_pos,
-                                 user_gesture);
+    browser->AddTabContents(contents, disposition, initial_pos,
+                            user_gesture);
   }
 }
 
@@ -142,7 +146,11 @@ void ExtensionHost::ShowCreatedWidget(int route_id,
                                       const gfx::Rect& initial_pos) {
   RenderWidgetHostView* widget_host_view =
       delegate_view_helper_.GetCreatedWidget(route_id);
-  GetBrowser()->BrowserRenderWidgetShowing();
+  Browser *browser = GetBrowser();
+  DCHECK(browser);
+  if (!browser)
+    return;
+  browser->BrowserRenderWidgetShowing();
   // TODO(erikkay): These two lines could be refactored with TabContentsView.
   widget_host_view->InitAsPopup(render_view_host()->view(), initial_pos);
   widget_host_view->GetRenderWidgetHost()->Init();
@@ -186,8 +194,11 @@ Browser* ExtensionHost::GetBrowser() {
 #endif
   Browser* browser = BrowserList::GetLastActiveWithProfile(
       render_view_host()->process()->profile());
-  // TODO(mpcomplete): what this verifies doesn't actually happen yet.
-  CHECK(browser) << "ExtensionHost running in Profile with no Browser active."
-      " It should have been deleted.";
+  // NOTE(rafaelw): This can return NULL in some circumstances. In particular,
+  // a toolstrip or background_page onload chrome.tabs api call can make it
+  // into here before the browser is sufficiently initialized to return here.
+  // A similar situation may arise during shutdown.
+  // TODO(rafaelw): Delay creation of background_page until the browser
+  // is available. http://code.google.com/p/chromium/issues/detail?id=13284
   return browser;
 }
diff --git a/chrome/browser/extensions/extension_tabs_module.cc b/chrome/browser/extensions/extension_tabs_module.cc
index a3868fa..ea1d3be 100644
--- a/chrome/browser/extensions/extension_tabs_module.cc
+++ b/chrome/browser/extensions/extension_tabs_module.cc
@@ -164,12 +164,20 @@ bool GetWindowFunction::RunImpl() {
 
 bool GetCurrentWindowFunction::RunImpl() {
   Browser* browser = dispatcher_->GetBrowser();
+  if (!browser) {
+    error_ = keys::kNoCurrentWindowError;
+    return false;
+  }
   result_.reset(CreateWindowValue(browser, false));
   return true;
 }
 
 bool GetLastFocusedWindowFunction::RunImpl() {
   Browser* browser = BrowserList::GetLastActiveWithProfile(profile());
+  if (!browser) {
+    error_ = keys::kNoLastFocusedWindowError;
+    return false;
+  }
   result_.reset(CreateWindowValue(browser, false));
   return true;
 }
@@ -218,7 +226,10 @@ bool CreateWindowFunction::RunImpl() {
   gfx::Rect bounds;
   bool maximized;
   // The call offsets the bounds by kWindowTilePixels (defined in WindowSizer to
-  // be 10).
+  // be 10)
+  //
+  // NOTE(rafaelw): It's ok if dispatcher_->GetBrowser() returns NULL here.
+  // GetBrowserWindowBounds will default to saved "default" values for the app.
   WindowSizer::GetBrowserWindowBounds(std::wstring(), empty_bounds,
                                       dispatcher_->GetBrowser(), &bounds,
                                       &maximized);
@@ -309,9 +320,6 @@ bool UpdateWindowFunction::RunImpl() {
     bounds.set_height(bounds_val);
   }
 
-  // TODO(rafaelw): This call to SetBounds() ends up resulting in the target
-  // window being activated (pushed to the front). On win32, this appears to be
-  // the result of HWND event handling.
   browser->window()->SetBounds(bounds);
   // TODO(rafaelw): Support |focused|.
   result_.reset(CreateWindowValue(browser, false));
@@ -342,16 +350,21 @@ bool GetSelectedTabFunction::RunImpl() {
   if (!args_->IsType(Value::TYPE_NULL)) {
     EXTENSION_FUNCTION_VALIDATE(args_->GetAsInteger(&window_id));
     browser = GetBrowserInProfileWithId(profile(), window_id, &error_);
-    if (!browser)
-      return false;
   } else {
     browser = dispatcher_->GetBrowser();
+    if (!browser)
+      error_ = keys::kNoCurrentWindowError;
   }
+  if (!browser)
+    return false;
 
   TabStripModel* tab_strip = browser->tabstrip_model();
-  result_.reset(ExtensionTabUtil::CreateTabValue(
-      tab_strip->GetSelectedTabContents(),
-      tab_strip,
+  TabContents* contents = tab_strip->GetSelectedTabContents();
+  if (!contents) {
+    error_ = keys::kNoSelectedTabError; 
+    return false;
+  }
+  result_.reset(ExtensionTabUtil::CreateTabValue(contents, tab_strip,
       tab_strip->selected_index()));
   return true;
 }
@@ -363,11 +376,13 @@ bool GetAllTabsInWindowFunction::RunImpl() {
   if (!args_->IsType(Value::TYPE_NULL)) {
     EXTENSION_FUNCTION_VALIDATE(args_->GetAsInteger(&window_id));
     browser = GetBrowserInProfileWithId(profile(), window_id, &error_);
-    if (!browser)
-      return false;
   } else {
     browser = dispatcher_->GetBrowser();
+    if (!browser)
+      error_ = keys::kNoCurrentWindowError;
   }
+  if (!browser)
+    return false;
 
   result_.reset(CreateTabList(browser));
 
@@ -385,11 +400,13 @@ bool CreateTabFunction::RunImpl() {
     EXTENSION_FUNCTION_VALIDATE(args->GetInteger(
         keys::kWindowIdKey, &window_id));
     browser = GetBrowserInProfileWithId(profile(), window_id, &error_);
-    if (!browser)
-      return false;
   } else {
-      browser = dispatcher_->GetBrowser();
+    browser = dispatcher_->GetBrowser();
+    if (!browser)
+      error_ = keys::kNoCurrentWindowError;
   }
+  if (!browser)
+    return false;
 
   TabStripModel* tab_strip = browser->tabstrip_model();
 
diff --git a/chrome/browser/extensions/extension_tabs_module_constants.cc b/chrome/browser/extensions/extension_tabs_module_constants.cc
index bf5e728..049f36a 100755
--- a/chrome/browser/extensions/extension_tabs_module_constants.cc
+++ b/chrome/browser/extensions/extension_tabs_module_constants.cc
@@ -34,8 +34,11 @@ const wchar_t kWindowIdKey[] = L"windowId";
 const char kStatusValueComplete[] = "complete";
 const char kStatusValueLoading[] = "loading";
 
+const char kNoCurrentWindowError[] = "No current window";
+const char kNoLastFocusedWindowError[] = "No last-focused window";
 const char kWindowNotFoundError[] = "No window with id: *.";
 const char kTabNotFoundError[] = "No tab with id: *.";
+const char kNoSelectedTabError[] = "No selected tab";
 const char kInvalidUrlError[] = "Invalid url: \"*\".";
 
 const char kGetWindowFunction[] = "GetWindow";
diff --git a/chrome/browser/extensions/extension_tabs_module_constants.h b/chrome/browser/extensions/extension_tabs_module_constants.h
index a990c5c..10abcf7 100755
--- a/chrome/browser/extensions/extension_tabs_module_constants.h
+++ b/chrome/browser/extensions/extension_tabs_module_constants.h
@@ -40,8 +40,11 @@ extern const char kStatusValueComplete[];
 extern const char kStatusValueLoading[];
 
 // Error messages.
+extern const char kNoCurrentWindowError[];
+extern const char kNoLastFocusedWindowError[];
 extern const char kWindowNotFoundError[];
 extern const char kTabNotFoundError[];
+extern const char kNoSelectedTabError[];
 extern const char kInvalidUrlError[];
 
 // Function names, Windows API.