Introduce unittest for passing NULL pointer for actual_range.

content/browser/renderer_host/render_widget_host_view_mac_unittest.mm

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/renderer_host/test_render_view_host.h"
@@ skipping 319 matching lines @@
   EXPECT_FALSE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
         ui::Range(2, 2).ToNSRange(),
         &rect,
         &actual_range));
 }
 
 TEST_F(RenderWidgetHostViewMacTest, UpdateCompositionSinglelineCase) {
   const gfx::Point kOrigin(10, 11);
   const gfx::Size kBoundsUnit(10, 20);
 
+  NSRect rect;
+  // Make sure not crashing by passing NULL pointer instead of |actual_range|.
+  EXPECT_FALSE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
+      ui::Range(0, 0).ToNSRange(),
+      &rect,
+      NULL));
+
   // If there are no update from renderer, always returned caret position.
-  NSRect rect;
   NSRange actual_range;
   EXPECT_FALSE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
       ui::Range(0, 0).ToNSRange(),
       &rect,
       &actual_range));
   EXPECT_FALSE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
       ui::Range(0, 1).ToNSRange(),
       &rect,
       &actual_range));
   EXPECT_FALSE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
@@ skipping 56 matching lines @@
                                                       0);
       const NSRange request_range = ui::Range(
           kCompositionStart + range.start(),
           kCompositionStart + range.end()).ToNSRange();
       EXPECT_TRUE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
             request_range,
             &rect,
             &actual_range));
       EXPECT_EQ(ui::Range(request_range), ui::Range(actual_range));
       EXPECT_EQ(expected_rect, gfx::Rect(NSRectToCGRect(rect)));
+
+      // Make sure not crashing by passing NULL pointer instead of
+      // |actual_range|.
+      EXPECT_TRUE(rwhv_mac_->GetCachedFirstRectForCharacterRange(
+            request_range,
+            &rect,
+            NULL));
     }
   }
 }
 
 TEST_F(RenderWidgetHostViewMacTest, UpdateCompositionMultilineCase) {
   const gfx::Point kOrigin(10, 11);
   const gfx::Size kBoundsUnit(10, 20);
   NSRect rect;
 
   const int kCompositionLength = 30;
@@ skipping 114 matching lines @@
   range = ui::Range(10, 20);
   EXPECT_TRUE(rwhv_mac_->GetCachedFirstRectForCharacterRange(range.ToNSRange(),
                                                              &rect,
                                                              &actual_range));
   EXPECT_EQ(ui::Range(10, 20), ui::Range(actual_range));
   EXPECT_EQ(
       GetExpectedRect(kOrigin, kBoundsUnit, ui::Range(0, 10), 1),
       gfx::Rect(NSRectToCGRect(rect)));
 }
 }  // namespace content