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

chrome/browser/extensions/extension_tabs_module.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/extension_tabs_module.h"
 
 #include "base/string_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/browser_window.h"
@@ skipping 146 matching lines @@
   Browser* browser = GetBrowserInProfileWithId(profile(), window_id, &error_);
   if (!browser)
     return false;
 
   result_.reset(CreateWindowValue(browser, false));
   return true;
 }
 
 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;
 }
 
 bool GetAllWindowsFunction::RunImpl() {
   bool populate_tabs = false;
   if (!args_->IsType(Value::TYPE_NULL)) {
     EXTENSION_FUNCTION_VALIDATE(args_->GetAsBoolean(&populate_tabs));
   }
 
@@ skipping 28 matching lines @@
         return false;
       }
     }
   }
 
   // Try to position the new browser relative its originating browser window.
   gfx::Rect empty_bounds;
   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);
 
   // Any part of the bounds can optionally be set by the caller.
   if (args_->IsType(Value::TYPE_DICTIONARY)) {
     const DictionaryValue *args = static_cast<const DictionaryValue*>(args_);
     int bounds_val;
     if (args->HasKey(keys::kLeftKey)) {
       EXTENSION_FUNCTION_VALIDATE(args->GetInteger(keys::kLeftKey,
@@ skipping 70 matching lines @@
     bounds.set_width(bounds_val);
   }
 
   if (update_props->HasKey(keys::kHeightKey)) {
     EXTENSION_FUNCTION_VALIDATE(update_props->GetInteger(
         keys::kHeightKey,
         &bounds_val));
     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));
 
   return true;
 }
 
 bool RemoveWindowFunction::RunImpl() {
   int window_id;
   EXTENSION_FUNCTION_VALIDATE(args_->GetAsInteger(&window_id));
@@ skipping 10 matching lines @@
 // Tabs ------------------------------------------------------------------------
 
 bool GetSelectedTabFunction::RunImpl() {
   Browser* browser;
   // windowId defaults to "current" window.
   int window_id = -1;
 
   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;
 }
 
 bool GetAllTabsInWindowFunction::RunImpl() {
   Browser* browser;
   // windowId defaults to "current" window.
   int window_id = -1;
   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));
 
   return true;
 }
 
 bool CreateTabFunction::RunImpl() {
   EXTENSION_FUNCTION_VALIDATE(args_->IsType(Value::TYPE_DICTIONARY));
   const DictionaryValue* args = static_cast<const DictionaryValue*>(args_);
 
   Browser *browser;
   // windowId defaults to "current" window.
   int window_id = -1;
   if (args->HasKey(keys::kWindowIdKey)) {
     EXTENSION_FUNCTION_VALIDATE(args->GetInteger(
         keys::kWindowIdKey, &window_id));
     browser = GetBrowserInProfileWithId(profile(), window_id, &error_);
+  } else {
+    browser = dispatcher_->GetBrowser();
     if (!browser)
-      return false;
-  } else {
-      browser = dispatcher_->GetBrowser();
+      error_ = keys::kNoCurrentWindowError;
   }
+  if (!browser)
+    return false;
 
   TabStripModel* tab_strip = browser->tabstrip_model();
 
   // TODO(rafaelw): handle setting remaining tab properties:
   // -title
   // -favIconUrl
 
   std::string url_string;
   scoped_ptr<GURL> url(new GURL());
   if (args->HasKey(keys::kUrlKey)) {
@@ skipping 263 matching lines @@
   if (ExtensionTabUtil::GetTabById(tab_id, profile, browser, tab_strip,
                                    contents, tab_index))
     return true;
 
   if (error_message)
     *error_message = ExtensionErrorUtils::FormatErrorMessage(
         keys::kTabNotFoundError, IntToString(tab_id));
 
   return false;
 }