[chromecast] Add cast_shell --accept-resource-provider switch and a utility function, GetSwitchValueBoolean.

Also has the cast_shell flag --accept-resource-provider imply
--alsa-check-close-timeout=0 unless the close timeout is explicitly
overridden.

BUG=internal b/26091363
TEST=pepperoni build
     cast_base_unittests --gtest_filter=ChromecastSwitchesTest.*

Review URL: https://codereview.chromium.org/1767603003

Cr-Commit-Position: refs/heads/master@{#380024}

6 files changed, 129 insertions, 3 deletions

diff --git a/chromecast/base/BUILD.gn b/chromecast/base/BUILD.gn
index fec43ac..c5a5445 100644
--- a/chromecast/base/BUILD.gn
+++ b/chromecast/base/BUILD.gn
@@ -91,6 +91,7 @@ source_set("test_support") {
 test("cast_base_unittests") {
   sources = [
     "bind_to_task_runner_unittest.cc",
+    "chromecast_switches_unittest.cc",
     "device_capabilities_impl_unittest.cc",
     "error_codes_unittest.cc",
     "path_utils_unittest.cc",
diff --git a/chromecast/base/chromecast_switches.cc b/chromecast/base/chromecast_switches.cc
index 469768c..baaf447 100644
--- a/chromecast/base/chromecast_switches.cc
+++ b/chromecast/base/chromecast_switches.cc
@@ -4,8 +4,16 @@
 
 #include "chromecast/base/chromecast_switches.h"
 
+#include "base/command_line.h"
+
 namespace switches {
 
+// Value indicating whether flag from command line switch is true.
+const char kSwitchValueTrue[] = "true";
+
+// Value indicating whether flag from command line switch is false.
+const char kSwitchValueFalse[] = "false";
+
 // Enable the CMA media pipeline.
 const char kEnableCmaMediaPipeline[] = "enable-cma-media-pipeline";
 
@@ -32,6 +40,11 @@ const char kLastLaunchedApp[] = "last-launched-app";
 // started.
 const char kPreviousApp[] = "previous-app";
 
+// Flag indicating that a resource provider must be set up to provide cast
+// receiver with resources. Apps cannot start until provided resources.
+// This flag implies --alsa-check-close-timeout=0.
+const char kAcceptResourceProvider[] = "accept-resource-provider";
+
 // Size of the ALSA output buffer in frames. This directly sets the latency of
 // the output device. Latency can be calculated by multiplying the sample rate
 // by the output buffer size.
@@ -48,7 +61,7 @@ const char kAlsaOutputStartThreshold[] = "alsa-output-start-threshold";
 const char kAlsaOutputAvailMin[] = "alsa-output-avail-min";
 
 // Time in ms to wait before closing the PCM handle when no more mixer inputs
-// remain.
+// remain. Assumed to be 0 if --accept-resource-provider is present.
 const char kAlsaCheckCloseTimeout[] = "alsa-check-close-timeout";
 
 // Number of channels on the alsa output device that the stream mixer uses.
@@ -56,3 +69,28 @@ const char kAlsaCheckCloseTimeout[] = "alsa-check-close-timeout";
 const char kAlsaNumOutputChannels[] = "alsa-num-output-channels";
 
 }  // namespace switches
+
+namespace chromecast {
+
+bool GetSwitchValueBoolean(const std::string& switch_string,
+                           const bool default_value) {
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switch_string)) {
+    if (command_line->GetSwitchValueASCII(switch_string) !=
+            switches::kSwitchValueTrue &&
+        command_line->GetSwitchValueASCII(switch_string) !=
+            switches::kSwitchValueFalse &&
+        command_line->GetSwitchValueASCII(switch_string) != "") {
+      LOG(WARNING) << "Invalid switch value " << switch_string << "="
+                   << command_line->GetSwitchValueASCII(switch_string)
+                   << "; assuming default value of " << default_value;
+      return default_value;
+    }
+    return command_line->GetSwitchValueASCII(switch_string) !=
+           switches::kSwitchValueFalse;
+  }
+  return default_value;
+}
+
+}  // namespace chromecast
diff --git a/chromecast/base/chromecast_switches.h b/chromecast/base/chromecast_switches.h
index 0d3094a..eecff02 100644
--- a/chromecast/base/chromecast_switches.h
+++ b/chromecast/base/chromecast_switches.h
@@ -5,10 +5,16 @@
 #ifndef CHROMECAST_BASE_CHROMECAST_SWITCHES_H_
 #define CHROMECAST_BASE_CHROMECAST_SWITCHES_H_
 
+#include <string>
+
 #include "build/build_config.h"
 
 namespace switches {
 
+// Switch values
+extern const char kSwitchValueTrue[];
+extern const char kSwitchValueFalse[];
+
 // Media switches
 extern const char kEnableCmaMediaPipeline[];
 extern const char kHdmiSinkSupportedCodecs[];
@@ -29,6 +35,9 @@ extern const char kAllowHiddenMediaPlayback[];
 extern const char kLastLaunchedApp[];
 extern const char kPreviousApp[];
 
+// Cast Receiver switches
+extern const char kAcceptResourceProvider[];
+
 // ALSA-based CMA switches. (Only valid for audio products.)
 extern const char kAlsaOutputBufferSize[];
 extern const char kAlsaOutputPeriodSize[];
@@ -39,4 +48,16 @@ extern const char kAlsaNumOutputChannels[];
 
 }  // namespace switches
 
+namespace chromecast {
+
+// Gets boolean value from switch |switch_string|.
+// --|switch_string| -> true
+// --|switch_string|="true" -> true
+// --|switch_string|="false" -> false
+// no switch named |switch_string| -> |default_value|
+bool GetSwitchValueBoolean(const std::string& switch_string,
+                           const bool default_value);
+
+}  // namespace chromecast
+
 #endif  // CHROMECAST_BASE_CHROMECAST_SWITCHES_H_
diff --git a/chromecast/base/chromecast_switches_unittest.cc b/chromecast/base/chromecast_switches_unittest.cc
new file mode 100644
index 0000000..465456e
--- /dev/null
+++ b/chromecast/base/chromecast_switches_unittest.cc
@@ -0,0 +1,61 @@
+// Copyright 2016 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 "base/command_line.h"
+#include "chromecast/base/chromecast_switches.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromecast {
+
+TEST(ChromecastSwitchesTest, NoSwitch) {
+  if (base::CommandLine::CommandLine::InitializedForCurrentProcess())
+    base::CommandLine::Reset();
+  base::CommandLine::Init(0, nullptr);
+  EXPECT_TRUE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, true));
+  EXPECT_FALSE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, false));
+}
+
+TEST(ChromecastSwitchesTest, NoSwitchValue) {
+  if (base::CommandLine::CommandLine::InitializedForCurrentProcess())
+    base::CommandLine::Reset();
+  base::CommandLine::Init(0, nullptr);
+  base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
+  cl->AppendSwitch(switches::kEnableCmaMediaPipeline);
+  EXPECT_TRUE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, true));
+  EXPECT_TRUE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, false));
+}
+
+TEST(ChromecastSwitchesTest, SwitchValueTrue) {
+  if (base::CommandLine::CommandLine::InitializedForCurrentProcess())
+    base::CommandLine::Reset();
+  base::CommandLine::Init(0, nullptr);
+  base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
+  cl->AppendSwitchASCII(switches::kEnableCmaMediaPipeline,
+                        switches::kSwitchValueTrue);
+  EXPECT_TRUE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, true));
+  EXPECT_TRUE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, false));
+}
+
+TEST(ChromecastSwitchesTest, SwitchValueFalse) {
+  if (base::CommandLine::CommandLine::InitializedForCurrentProcess())
+    base::CommandLine::Reset();
+  base::CommandLine::Init(0, nullptr);
+  base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
+  cl->AppendSwitchASCII(switches::kEnableCmaMediaPipeline,
+                        switches::kSwitchValueFalse);
+  EXPECT_FALSE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, true));
+  EXPECT_FALSE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, false));
+}
+
+TEST(ChromecastSwitchesTest, SwitchValueNonsense) {
+  if (base::CommandLine::CommandLine::InitializedForCurrentProcess())
+    base::CommandLine::Reset();
+  base::CommandLine::Init(0, nullptr);
+  base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
+  cl->AppendSwitchASCII(switches::kEnableCmaMediaPipeline, "silverware");
+  EXPECT_TRUE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, true));
+  EXPECT_FALSE(GetSwitchValueBoolean(switches::kEnableCmaMediaPipeline, false));
+}
+
+}  // namespace chromecast
diff --git a/chromecast/chromecast_tests.gypi b/chromecast/chromecast_tests.gypi
index a5794038..88dfba9 100644
--- a/chromecast/chromecast_tests.gypi
+++ b/chromecast/chromecast_tests.gypi
@@ -21,6 +21,7 @@
       ],
       'sources': [
         'base/bind_to_task_runner_unittest.cc',
+        'base/chromecast_switches_unittest.cc',
         'base/component/component_unittest.cc',
         'base/device_capabilities_impl_unittest.cc',
         'base/error_codes_unittest.cc',
diff --git a/chromecast/media/cma/backend/alsa/stream_mixer_alsa.cc b/chromecast/media/cma/backend/alsa/stream_mixer_alsa.cc
index 2f1afc7..5e5e17b 100644
--- a/chromecast/media/cma/backend/alsa/stream_mixer_alsa.cc
+++ b/chromecast/media/cma/backend/alsa/stream_mixer_alsa.cc
@@ -256,9 +256,13 @@ void StreamMixerAlsa::DefineAlsaParameters() {
   }
   alsa_avail_min_ = avail_min;
 
+  // --accept-resource-provider should imply a check close timeout of 0.
+  int default_close_timeout = chromecast::GetSwitchValueBoolean(
+                                  switches::kAcceptResourceProvider, false)
+                                  ? 0
+                                  : kDefaultCheckCloseTimeoutMs;
   GetSwitchValueAsNonNegativeInt(switches::kAlsaCheckCloseTimeout,
-                                 kDefaultCheckCloseTimeoutMs,
-                                 &check_close_timeout_);
+                                 default_close_timeout, &check_close_timeout_);
 }
 
 int StreamMixerAlsa::SetAlsaPlaybackParams() {