Resolve several Chromoting Android UI-related crashes and misbehaviors

This protects several places where the UI once allowed users to hit dangerous edge cases:
- Canceling the auth prompt on the app's first run now leaves the switcher's label text unset.
- Launching the app on a device with no usable accounts once again offers to add a new account.
- Trying to authenticate to an account for the first time while disconnected is detected as a network problem.
- The account switcher is made unavailable when the only usable account is already selected.
- There's a new refresh button for updating the currently-displayed host list from the directory server.
- Pressing a device's extra/exotic buttons with high keycodes no longer DCHECKS to crash the app.
- Many third-party keyboards that stubbornly covered the bottom of the remote desktop image no longer do so.
- All native threads are actually properly detached from the JVM.

BUG=259594

Review URL: https://chromiumcodereview.appspot.com/22662003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@216556 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 29 insertions, 6 deletions

diff --git a/remoting/client/jni/android_keymap.cc b/remoting/client/jni/android_keymap.cc
index 743e15e..45d67c4 100644
--- a/remoting/client/jni/android_keymap.cc
+++ b/remoting/client/jni/android_keymap.cc
@@ -199,12 +199,15 @@ const uint32 usb_keycodes[] = {
   0x0700b7,  // NUMPAD_RIGHT_PAREN
 };
 
-}
+}  // namespace
 
 namespace remoting {
 
 uint32 AndroidKeycodeToUsbKeycode(size_t android) {
-  DCHECK_LT(android, sizeof (usb_keycodes) / sizeof (uint32));
+  if (android >= sizeof (usb_keycodes) / sizeof (uint32)) {
+    LOG(WARNING) << "Attempted to decode out-of-range Android keycode";
+    return 0;
+  }
 
   return usb_keycodes[android];
 }
diff --git a/remoting/client/jni/chromoting_jni_instance.cc b/remoting/client/jni/chromoting_jni_instance.cc
index 3e11b2fa..b68aab9 100644
--- a/remoting/client/jni/chromoting_jni_instance.cc
+++ b/remoting/client/jni/chromoting_jni_instance.cc
@@ -132,8 +132,7 @@ void ChromotingJniInstance::PerformKeyboardAction(int key_code, bool key_down) {
     action.set_usb_keycode(usb_code);
     action.set_pressed(key_down);
     connection_->input_stub()->InjectKeyEvent(action);
-  }
-  else {
+  } else {
     LOG(WARNING) << "Ignoring unknown keycode: " << key_code;
   }
 }
diff --git a/remoting/client/jni/chromoting_jni_runtime.cc b/remoting/client/jni/chromoting_jni_runtime.cc
index 8fa9018..8d51a83 100644
--- a/remoting/client/jni/chromoting_jni_runtime.cc
+++ b/remoting/client/jni/chromoting_jni_runtime.cc
@@ -7,6 +7,7 @@
 #include "base/android/base_jni_registrar.h"
 #include "base/android/jni_android.h"
 #include "base/memory/singleton.h"
+#include "base/synchronization/waitable_event.h"
 #include "media/base/yuv_convert.h"
 #include "net/android/net_jni_registrar.h"
 #include "remoting/base/url_request_context.h"
@@ -68,8 +69,19 @@ ChromotingJniRuntime::~ChromotingJniRuntime() {
 
   JNIEnv* env = base::android::AttachCurrentThread();
   env->DeleteGlobalRef(class_);
-  // TODO(solb): Detach all threads from JVM here.
-  // crbug.com/259594
+
+  base::WaitableEvent done_event(false, false);
+  network_task_runner_->PostTask(FROM_HERE, base::Bind(
+      &ChromotingJniRuntime::DetachFromVmAndSignal,
+      base::Unretained(this),
+      &done_event));
+  done_event.Wait();
+  display_task_runner_->PostTask(FROM_HERE, base::Bind(
+      &ChromotingJniRuntime::DetachFromVmAndSignal,
+      base::Unretained(this),
+      &done_event));
+  done_event.Wait();
+  base::android::DetachFromVM();
 }
 
 void ChromotingJniRuntime::ConnectToHost(const char* username,
@@ -178,4 +190,9 @@ void ChromotingJniRuntime::RedrawCanvas() {
       env->GetStaticMethodID(class_, "redrawGraphicsInternal", "()V"));
 }
 
+void ChromotingJniRuntime::DetachFromVmAndSignal(base::WaitableEvent* waiter) {
+  base::android::DetachFromVM();
+  waiter->Signal();
+}
+
 }  // namespace remoting
diff --git a/remoting/client/jni/chromoting_jni_runtime.h b/remoting/client/jni/chromoting_jni_runtime.h
index 1a6952b..93f933f 100644
--- a/remoting/client/jni/chromoting_jni_runtime.h
+++ b/remoting/client/jni/chromoting_jni_runtime.h
@@ -6,6 +6,7 @@
 #define REMOTING_CLIENT_JNI_CHROMOTING_JNI_RUNTIME_H_
 
 #include <jni.h>
+#include <string>
 
 #include "base/at_exit.h"
 #include "net/url_request/url_request_context_getter.h"
@@ -94,6 +95,9 @@ class ChromotingJniRuntime {
   // cross-thread calls on the class.
   virtual ~ChromotingJniRuntime();
 
+  // Detaches JVM from the current thread, then signals. Doesn't own |waiter|.
+  void DetachFromVmAndSignal(base::WaitableEvent* waiter);
+
   // Reference to the Java class into which we make JNI calls.
   jclass class_;