make allocPixels throw on failure

samplecode/SampleApp.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleApp.h"
 
 #include "OverView.h"
@@ skipping 981 matching lines @@
 void SampleWindow::listTitles() {
     int count = fSamples.count();
     SkDebugf("All Slides:\n");
     for (int i = 0; i < count; i++) {
         SkDebugf("    %s\n", getSampleTitle(i).c_str());
     }
 }
 
 static SkBitmap capture_bitmap(SkCanvas* canvas) {
     SkBitmap bm;
-    if (bm.allocPixels(canvas->imageInfo())) {
+    if (bm.tryAllocPixels(canvas->imageInfo())) {
         canvas->readPixels(&bm, 0, 0);
     }
     return bm;
 }
 
 static bool bitmap_diff(SkCanvas* canvas, const SkBitmap& orig,
                         SkBitmap* diff) {
     SkBitmap src = capture_bitmap(canvas);
 
     SkAutoLockPixels alp0(src);
@@ skipping 1383 matching lines @@
     setenv("ANDROID_ROOT", "/android/device/data", 0);
 #endif
     SkGraphics::Init();
     SkEvent::Init();
 }
 
 void application_term() {
     SkEvent::Term();
     SkGraphics::Term();
 }