Yet more ASAN fixes.

tests/ImageFilterTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkBitmapDevice.h"
 #include "SkBitmapSource.h"
@@ skipping 1123 matching lines @@
     SkImageFilter::Context ctx(SkMatrix::I(), SkIRect::MakeLargest(), NULL);
     REPORTER_ASSERT(reporter, composedFilter->filterImage(&proxy, bitmap, ctx, &result, &offset));
     REPORTER_ASSERT(reporter, offset.fX == 1 && offset.fY == 0);
 }
 
 #if SK_SUPPORT_GPU
 const SkSurfaceProps gProps = SkSurfaceProps(SkSurfaceProps::kLegacyFontHost_InitType);
 
 DEF_GPUTEST(ImageFilterCropRectGPU, reporter, factory) {
     GrContext* context = factory->get(static_cast<GrContextFactory::GLContextType>(0));
+    if (NULL == context) {
+        return;
+    }
     SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(context,
                                                          SkSurface::kNo_Budgeted,
                                                          SkImageInfo::MakeN32Premul(100, 100),
                                                          0,
                                                          &gProps));
     test_crop_rects(device, reporter);
 }
 
 DEF_GPUTEST(HugeBlurImageFilterGPU, reporter, factory) {
     GrContext* context = factory->get(static_cast<GrContextFactory::GLContextType>(0));
+    if (NULL == context) {
+        return;
+    }
     SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(context,
                                                          SkSurface::kNo_Budgeted,
                                                          SkImageInfo::MakeN32Premul(100, 100),
                                                          0,
                                                          &gProps));
     test_huge_blur(device, reporter);
 }
 
 DEF_GPUTEST(XfermodeImageFilterCroppedInputGPU, reporter, factory) {
     GrContext* context = factory->get(static_cast<GrContextFactory::GLContextType>(0));
+    if (NULL == context) {
+        return;
+    }
     SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(context,
                                                          SkSurface::kNo_Budgeted,
                                                          SkImageInfo::MakeN32Premul(1, 1),
                                                          0,
                                                          &gProps));
     test_xfermode_cropped_input(device, reporter);
 }
 
 DEF_GPUTEST(TestNegativeBlurSigmaGPU, reporter, factory) {
     GrContext* context = factory->get(static_cast<GrContextFactory::GLContextType>(0));
+    if (NULL == context) {
+        return;
+    }
     SkAutoTUnref<SkGpuDevice> device(SkGpuDevice::Create(context,
                                                          SkSurface::kNo_Budgeted,
                                                          SkImageInfo::MakeN32Premul(1, 1),
                                                          0,
                                                          &gProps));
     test_negative_blur_sigma(device, reporter);
 }
 #endif