Fixing the bug that occurs when the hover shader becomes null due to small ta...

chrome/browser/ui/views/tabs/tab.cc

 // Copyright (c) 2010 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/ui/views/tabs/tab.h"
 
 #include <limits>
 
 #include "app/multi_animation.h"
 #include "app/resource_bundle.h"
@@ skipping 585 matching lines @@
   }
   colors[0] = SkColorSetARGB(hover_alpha, 255, 255, 255);
   colors[1] = SkColorSetARGB(0, 255, 255, 255);
   SkShader* shader = SkGradientShader::CreateRadial(
       loc,
       SkIntToScalar(radius),
       colors,
       NULL,
       2,
       SkShader::kClamp_TileMode);
-  paint.setShader(shader);
-  shader->unref();
-  hover_canvas.DrawRectInt(hover_point_.x() - radius,
-                           hover_point_.y() - radius,
-                           radius * 2, radius * 2, paint);
-
+  // Shader can end up null when radius = 0.
+  // If so, this results in default full tab glow behavior.
+  if (shader) {
+    paint.setShader(shader);
+    shader->unref();
+    hover_canvas.DrawRectInt(hover_point_.x() - radius,
+                             hover_point_.y() - radius,
+                             radius * 2, radius * 2, paint);
+  }
   return hover_canvas.ExtractBitmap();
 }
 
 int Tab::IconCapacity() const {
   if (height() < GetMinimumUnselectedSize().height())
     return 0;
   return (width() - kLeftPadding - kRightPadding) / kFavIconSize;
 }
 
 bool Tab::ShouldShowIcon() const {
@@ skipping 39 matching lines @@
   tab_active.image_r = rb.GetBitmapNamed(IDR_TAB_ACTIVE_RIGHT);
   tab_active.l_width = tab_active.image_l->width();
   tab_active.r_width = tab_active.image_r->width();
 
   tab_inactive.image_l = rb.GetBitmapNamed(IDR_TAB_INACTIVE_LEFT);
   tab_inactive.image_c = rb.GetBitmapNamed(IDR_TAB_INACTIVE_CENTER);
   tab_inactive.image_r = rb.GetBitmapNamed(IDR_TAB_INACTIVE_RIGHT);
   tab_inactive.l_width = tab_inactive.image_l->width();
   tab_inactive.r_width = tab_inactive.image_r->width();
 }