Suppress browser microdump when renderer crashes in multiprocess WebView.

components/crash/content/app/breakpad_linux.cc

Index: components/crash/content/app/breakpad_linux.cc
diff --git a/components/crash/content/app/breakpad_linux.cc b/components/crash/content/app/breakpad_linux.cc
index 6e78cb8028f500f9b93a2235a165ee814047c767..230799e81b6a124ab11ab48270167589f2b30d4e 100644
--- a/components/crash/content/app/breakpad_linux.cc
+++ b/components/crash/content/app/breakpad_linux.cc
@@ -101,6 +101,8 @@ ExceptionHandler* g_breakpad = nullptr;
 const char* g_asan_report_str = nullptr;
 #endif
 #if defined(OS_ANDROID)
+#define G_DUMPS_SUPPRESSED_MAGIC 0x5AFECEDE
+uint32_t g_dumps_suppressed = 0;
 char* g_process_type = nullptr;
 ExceptionHandler* g_microdump = nullptr;
 int g_signal_code_pipe_fd = -1;
@@ -576,13 +578,27 @@ void WriteAndroidPackage(MimeWriter& writer,
 #endif  // defined(OS_ANDROID)
 
 void DumpProcess() {
-  if (g_breakpad)
-    g_breakpad->WriteMinidump();
-
 #if defined(OS_ANDROID)
+  // Don't use g_breakpad and g_microdump directly here, because their
+  // output might currently be suppressed.
+  if (g_breakpad) {
+    ExceptionHandler(g_breakpad->minidump_descriptor(),
+                     nullptr,
+                     CrashDoneNoUpload,
+                     nullptr,
+                     false, -1).WriteMinidump();
+  }
   // If microdumps are enabled write also a microdump on the system log.
-  if (g_microdump)
-    g_microdump->WriteMinidump();
+  if (g_microdump) {
+    ExceptionHandler(g_microdump->minidump_descriptor(),
+                     nullptr,
+                     MicrodumpCrashDone,
+                     nullptr,
+                     false, -1).WriteMinidump();
+  }
+#else
+  if (g_breakpad)
+    g_breakpad->WriteMinidump();
 #endif
 }
 
@@ -603,6 +619,10 @@ size_t WriteNewline() {
 }
 
 #if defined(OS_ANDROID)
+bool ShouldGenerateDump(void *context) {
+  return g_dumps_suppressed != G_DUMPS_SUPPRESSED_MAGIC;
+}
+
 void AndroidLogWriteHorizontalRule() {
   __android_log_write(ANDROID_LOG_WARN, kGoogleBreakpad,
                       "### ### ### ### ### ### ### ### ### ### ### ### ###");
@@ -756,7 +776,7 @@ void EnableCrashDumping(bool unattended) {
   if (unattended) {
     g_breakpad = new ExceptionHandler(
         minidump_descriptor,
-        nullptr,
+        ShouldGenerateDump,

[Torne, 2017/01/16 12:08:57]

Does this need to be #if defined(OS_ANDROID)? The definition of the function
above is..

[Tobias Sargeant, 2017/01/16 14:01:36]

It certainly should be. Thanks.

         CrashDoneNoUpload,
         nullptr,
         true,  // Install handlers.
@@ -865,8 +885,8 @@ void EnableNonBrowserCrashDumping(const std::string& process_type,
   const size_t process_type_len = process_type.size() + 1;
   g_process_type = new char[process_type_len];
   strncpy(g_process_type, process_type.c_str(), process_type_len);
-  new google_breakpad::ExceptionHandler(MinidumpDescriptor(minidump_fd),
-      nullptr, CrashDoneInProcessNoUpload, nullptr, true, -1);
+  new ExceptionHandler(MinidumpDescriptor(minidump_fd), ShouldGenerateDump,
+                       CrashDoneInProcessNoUpload, nullptr, true, -1);
 }
 
 void MicrodumpInfo::SetGpuFingerprint(const std::string& gpu_fingerprint) {
@@ -923,7 +943,7 @@ void MicrodumpInfo::Initialize(const std::string& process_type,
   }
 
   g_microdump =
-      new ExceptionHandler(descriptor, nullptr, MicrodumpCrashDone,
+      new ExceptionHandler(descriptor, ShouldGenerateDump, MicrodumpCrashDone,
                            reinterpret_cast<void*>(is_browser_process),
                            true,  // Install handlers.
                            -1);   // Server file descriptor. -1 for in-process.
@@ -1946,6 +1966,10 @@ void GenerateMinidumpOnDemandForAndroid(int dump_fd) {
         .WriteMinidump();
   }
 }
+
+void SuppressDumpGeneration() {
+  g_dumps_suppressed = G_DUMPS_SUPPRESSED_MAGIC;
+}
 #endif  // OS_ANDROID
 
 bool IsCrashReporterEnabled() {