base: Cleanup class/struct forward declarations

Remove useless class and struct forward declarations, and add
missing ones in base header files.

BUG=662195
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel

Review-Url: https://codereview.chromium.org/2479683004
Cr-Commit-Position: refs/heads/master@{#430160}

base/android/java_handler_thread.h

@@ -14,7 +14,6 @@
 namespace base {
 
 class MessageLoop;
-class WaitableEvent;
 
 namespace android {
 

base/android/java_message_handler_factory.h

@@ -11,6 +11,7 @@
 namespace base {
 
 class MessagePumpForUI;
+class WaitableEvent;
 
 namespace android {
 

base/debug/activity_tracker.h

@@ -33,7 +33,6 @@ struct PendingTask;
 
 class FilePath;
 class Lock;
-class MemoryMappedFile;
 class PlatformThreadHandle;
 class Process;
 class WaitableEvent;

base/files/file_proxy.h

@@ -15,10 +15,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 
-namespace tracked_objects {
-class Location;
-};
-
 namespace base {
 
 class TaskRunner;

base/files/important_file_writer.h

@@ -20,7 +20,6 @@
 namespace base {
 
 class SequencedTaskRunner;
-class Thread;
 
 // Helper for atomically writing a file to ensure that it won't be corrupted by
 // *application* crash during write (implemented as create, flush, rename).

base/mac/bundle_locations.h

@@ -12,7 +12,6 @@
 #import <Foundation/Foundation.h>
 #else  // __OBJC__
 class NSBundle;
-class NSString;
 #endif  // __OBJC__
 
 namespace base {

base/memory/shared_memory_handle.h

@@ -24,8 +24,6 @@
 
 namespace base {
 
-class Pickle;
-
 // SharedMemoryHandle is a platform specific type which represents
 // the underlying OS handle to a shared memory segment.
 #if defined(OS_POSIX) && !(defined(OS_MACOSX) && !defined(OS_IOS))

base/message_loop/incoming_task_queue.h

@@ -16,7 +16,6 @@
 namespace base {
 
 class MessageLoop;
-class WaitableEvent;
 
 namespace internal {
 

base/metrics/histogram.h

@@ -92,7 +92,6 @@ class BooleanHistogram;
 class CustomHistogram;
 class Histogram;
 class LinearHistogram;
-class PersistentMemoryAllocator;
 class Pickle;
 class PickleIterator;
 class SampleVector;

base/metrics/histogram_base.h

@@ -21,7 +21,6 @@
 
 namespace base {
 
-class BucketRanges;
 class DictionaryValue;
 class HistogramBase;
 class HistogramSamples;

base/metrics/persistent_histogram_allocator.h

@@ -19,6 +19,7 @@
 
 namespace base {
 
+class BucketRanges;
 class FilePath;
 class PersistentSampleMapRecords;
 class PersistentSparseHistogramDataManager;

base/metrics/persistent_sample_map.h

@@ -24,7 +24,6 @@ namespace base {
 
 class PersistentHistogramAllocator;
 class PersistentSampleMapRecords;
-class PersistentSparseHistogramDataManager;
 
 // The logic here is similar to that of SampleMap but with different data
 // structures. Changes here likely need to be duplicated there.

base/metrics/statistics_recorder.h

@@ -26,8 +26,6 @@
 #include "base/metrics/histogram_base.h"
 #include "base/strings/string_piece.h"
 
-class SubprocessMetricsProviderTest;
-
 namespace base {
 
 class BucketRanges;

base/synchronization/waitable_event_watcher.h

@@ -21,7 +21,6 @@ namespace base {
 
 class Flag;
 class AsyncWaiter;
-class AsyncCallbackTask;
 class WaitableEvent;
 
 // This class provides a way to wait on a WaitableEvent asynchronously.

base/task_scheduler/task_scheduler_impl.h

@@ -30,7 +30,6 @@ class SchedulerWorkerPoolParams;
 namespace internal {
 
 class DelayedTaskManager;
-class SchedulerServiceThread;
 class TaskTracker;
 
 // Default TaskScheduler implementation. This class is thread-safe.

base/task_scheduler/test_task_factory.h

@@ -20,9 +20,6 @@
 #include "base/threading/thread_checker_impl.h"
 
 namespace base {
-
-class WaitableEvent;
-
 namespace internal {
 namespace test {
 

base/test/launcher/test_launcher.h

@@ -21,11 +21,6 @@
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
-namespace testing {
-class TestCase;
-class TestInfo;
-}
-
 namespace base {
 
 class CommandLine;

base/third_party/libevent/http-internal.h

@@ -31,7 +31,6 @@ enum evhttp_connection_error {
 };
 
 struct evbuffer;
-struct addrinfo;
 struct evhttp_request;
 
 /* A stupid connection object - maybe make this a bufferevent later */

base/threading/worker_pool.h

@@ -9,8 +9,6 @@
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 
-class Task;
-
 namespace tracked_objects {
 class Location;
 }  // namespace tracked_objects

base/threading/worker_pool_posix.h

@@ -38,8 +38,6 @@
 #include "base/threading/platform_thread.h"
 #include "base/tracked_objects.h"
 
-class Task;
-
 namespace base {
 
 class BASE_EXPORT PosixDynamicThreadPool

base/trace_event/memory_allocator_dump.h

@@ -19,7 +19,6 @@
 namespace base {
 namespace trace_event {
 
-class MemoryDumpManager;
 class ProcessMemoryDump;
 class TracedValue;
 

base/trace_event/process_memory_dump.h

@@ -31,7 +31,6 @@
 namespace base {
 namespace trace_event {
 
-class MemoryDumpManager;
 class MemoryDumpSessionState;
 class TracedValue;
 

base/trace_event/trace_event_impl.h

@@ -28,10 +28,6 @@
 #include "build/build_config.h"
 
 namespace base {
-
-class WaitableEvent;
-class MessageLoop;
-
 namespace trace_event {
 
 typedef base::Callback<bool(const char* arg_name)> ArgumentNameFilterPredicate;

base/trace_event/trace_event_synthetic_delay.h

@@ -62,9 +62,6 @@
     trace_event_internal::GetOrCreateDelay(name, &impl_ptr)->End();   \
   } while (false)
 
-template <typename Type>
-struct DefaultSingletonTraits;
-
 namespace base {
 namespace trace_event {
 

base/trace_event/trace_log.h

@@ -26,6 +26,7 @@ namespace base {
 
 template <typename Type>
 struct DefaultSingletonTraits;
+class MessageLoop;
 class RefCountedString;
 
 namespace trace_event {

cc/test/fake_raster_source.h

@@ -12,6 +12,10 @@
 
 class SkCanvas;
 
+namespace base {
+class WaitableEvent;
+}
+
 namespace cc {
 
 class RecordingSource;