Support AudioContextOptions latencyHint as double.

third_party/WebKit/Source/modules/webaudio/AudioContextTest.cpp

Index: third_party/WebKit/Source/modules/webaudio/AudioContextTest.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioContextTest.cpp b/third_party/WebKit/Source/modules/webaudio/AudioContextTest.cpp
index a76bd7beb6c200d93fd7d62602ea9445a5f9a5b9..fd301035be92e5521791e4bf415076dc6d992533 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioContextTest.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/AudioContextTest.cpp
@@ -50,6 +50,12 @@ class AudioContextTestPlatform : public TestingPlatformSupport {
       case WebAudioLatencyHint::kCategoryPlayback:
         bufferSize = audioHardwareBufferSize() * 4;
         break;
+      case WebAudioLatencyHint::kCategoryExact:
+        bufferSize = std::max(
+            static_cast<double>(audioHardwareBufferSize()),
+            std::min(latencyHint.seconds() * audioHardwareSampleRate(),
+                     static_cast<double>(audioHardwareBufferSize() * 4)));
+        break;
       default:
         NOTREACHED();
         break;
@@ -99,6 +105,29 @@ TEST_F(AudioContextTest, AudioContextOptions_WebAudioLatencyHint) {
   AudioContext* playbackContext =
       AudioContext::create(document(), playbackOptions, ASSERT_NO_EXCEPTION);
   EXPECT_GT(playbackContext->baseLatency(), balancedContext->baseLatency());
+
+  AudioContextOptions exactTooSmallOptions;
+  exactTooSmallOptions.setLatencyHint(
+      AudioContextLatencyCategoryOrDouble::fromDouble(0.000001));
+  AudioContext* exactTooSmallContext = AudioContext::create(
+      document(), exactTooSmallOptions, ASSERT_NO_EXCEPTION);
+  EXPECT_EQ(exactTooSmallContext->baseLatency(),
+            interactiveContext->baseLatency());
+
+  const double exactLatencySec = 0.01;
+  AudioContextOptions exactOkOptions;
+  exactOkOptions.setLatencyHint(
+      AudioContextLatencyCategoryOrDouble::fromDouble(exactLatencySec));
+  AudioContext* exactOkContext =
+      AudioContext::create(document(), exactOkOptions, ASSERT_NO_EXCEPTION);
+  EXPECT_EQ(exactOkContext->baseLatency(), exactLatencySec * 2);
+
+  AudioContextOptions exactTooBigOptions;
+  exactTooBigOptions.setLatencyHint(
+      AudioContextLatencyCategoryOrDouble::fromDouble(1));
+  AudioContext* exactTooBigContext =
+      AudioContext::create(document(), exactTooBigOptions, ASSERT_NO_EXCEPTION);
+  EXPECT_EQ(exactTooBigContext->baseLatency(), playbackContext->baseLatency());
 }
 
 }  // namespace blink